Complete Electrical Substations for Electrical Engineering | Ahmed Mahdy | Skillshare

Complete Electrical Substations for Electrical Engineering

Ahmed Mahdy, Electrical Power Engineer

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35 Lessons (3h 31m)
    • 1. Introduction To Electrical Substations

    • 2. What is An Electrical Substation ?

    • 3. Function of Substations

    • 4. Classification of Substations

    • 5. Relation between Voltage and Substations

    • 6. Construction of Substation

    • 7. Electrical Power Transformer

    • 8. Why do we Step up and Step down the Voltage ?

    • 9. Lightening Arrester

    • 10. Current and Potential Transformers

    • 11. Capacitor Voltage Transformer

    • 12. Wave Trap

    • 13. Busbars

    • 14. Circuit Breakers and Relays

    • 15. Priniciple of Operation of Relay

    • 16. Types of Relays according to Function

    • 17. Types of Relays according to Construction

    • 18. Types of Relays according to Time Characteristics

    • 19. Isolator

    • 20. DC Power Supply

    • 21. Supply Line

    • 22. Construction Of Underground Cables

    • 23. Construction Of Over Head Transmission Lines

    • 24. Comparison Between Underground Cables And Overhead Transmission Lines

    • 25. Types Of Circuit Breakers And Fuses

    • 26. Types Of Switches In Power System And Substations

    • 27. Importance Of Capacitor Banks In Power System

    • 28. Importance Of Ring Main Unit In Power System

    • 29. Air Insulated Substation and Gas Insulated Substation

    • 30. Different BusBar Schemes of Substations

    • 31. What Is IP Or Ingress Protection

    • 32. Selection Of Busbars In Electrical Substation

    • 33. Design of Substations

    • 34. Single Line Diagram Of 66 To 11KV Substation

    • 35. Extra Images


About This Class

​Welcome to my own course in my series for power system explanations, in this course we are going to discuss the following topics related to electrical power substations:

  1. We will discuss function, classification and voltage of electrical substations.

  2. We will discuss its main components like power transformers, conductors, insulators, switch gears, current transformer, capacitor voltage transformer and voltage transformer.

  3. We will discuss the different types of circuit breakers, relays and their classification according to time, construction and function.

  4. We will discuss the difference between circuit breaker and fuse, in addition to their applications.

  5. We will understand the definition of IP or ingress protection.

  6. We will explain the grounding system including the effect of current on human body, components of grounding system, types of electric hazards and classification of earthing system.

  7. We will measure the earthing resistance by Megger and three point method.

  8. We will learn how to do an earthing system using Etap program.

  9. We will learn about the ring main unit and its importance in electrical power system.

  10. We will discuss the types of switches used in electrical power system and substations.

  11. We will discuss the overhead transmission lines, underground cables and difference between them.

  12. We will learn about busbars in power system, its importance, its different schemes and how to select them.

  13. We will understand the lightning arrester and wave trap which are used in substations.

  14. We will discuss the air and gas insulated substations.

  15. We will discuss how to design an electrical substation and single line diagram of 66/11 kV substation.

And much more,

See you in my own course .


1. Introduction To Electrical Substations: hi and welcome everyone to my own course for electrical substations. I am a mad Maddy and electrical power engineer. So what is this course? A power It Z discourse up with electrical substations in electrical power system. So what is the content off our course? Well, first we are going to discuss is the function classification and the voltage levels off the electrical substations. Then we're going to discuss the main components, such as the power transformers used the type of conductors such as the underground cables and the overhead transmission line. The insulators used the switching gears, the definition off switching years, the city or the current transformer, Zyvox Transformer and capacitor World transformer. We will discuss also the different types of circuit breakers used, such as the air circuit breaker, the vacuum and F sex, the relays which are used, and their classification according to's their construction, buying and function. We will discuss also the difference between circuit breaker and suffuse and their applications. We will understand dizzy definition off the I B or the Angus protection, which is used in every electrical equipment. Then we're going to explain everything about the grounding system, including the effect off the current on the human body D. C or A C. The components off the grounding systems, the types off the electric hazards, the classifications off er thing system. Then we're going toe measure the earthy resistance by using Z maker and another missile holds a three point message. Then we will learn how to do a nursing system using the teeter program. Then, when we are going to learn about the Bangemann unit and its importance in electrical power system, we will discuss also the pipes off the switches used in electrical pole system and substations we will discuss is the overhead transmission lines, underground cables and the difference or comparison between them. We will also learn about the passport in electrical power system, their importance and their different passport schemes, and how to select them in our power system or in our electrical power station. We will understand also the lightning arrest or and with trap, which are used in electrical substations and their importance. We will also goingto discusses the air and the gas insulated substations we will discuss also have toe design, an electrical substation and finally the single line diagram off a 66/11 kilovolts substation. So this is our large course containing a lot off content, which will help you as an electrical engineer or specifically, an electrical power engineer, and help you to learn a lot off topics in one course. So I hope to see you on my own course. And for any question, any time you can send me a message. Thank you. 2. What is An Electrical Substation ?: hello and welcome everyone to my own course for electrical substations. So what is electrical substation? An electrical substation is simply a part off an electrical generation transmission and distribution system so the substation can be found near and electrical generation or an electrical transmission system and distribution system. Substation transform is a voltage from the high value toe, a low value or reverse according toe, their place in support system. For example, if we are talking about substation, which is near an electrical generating the power plant, therefore this substation will just to be used toe step up the voltage from 3.3 kilovolt toe, 220 kilovolts or 500 kilovolts, according toe the transmission system. If we're talking about with that distribution system, we can step down the voltage from 60 60 care of alter toe 11 kilovolts. So according toe, that place or the position off the substation. In our power system, we can use that substation. Toe transform is a voltage from high to low value or the reverse. The first substations were only connected toe only one power station. Why? Because in the past we have only one power plant because our consumption off electricity waas very low. So the first substations were only connected toe only one power station. In the next lecture, we are going to discuss the function off the electrical substation. 3. Function of Substations: So what is the function off substation Number one. It is used the force of protection off the transmission system because is that substation includes protective the prices as circuit breakers and relates. It contains current transformers and the voltage transformers which you are going to discuss in this course it is used to control the exact change off energy because of substations is between that generation and transmission and between the transmission and the distribution. Therefore, it controls the flow off the bar or the exit change off the energy between each off these different systems. It ensured a steady state and transient stability is a steady state and transient stability fields are a very large and important fields. You will find that the steady state representatives there is stability off support system support system when it supplies a constant amount of power. The transient stability represented that the behavior officer system when disturbance happen. If our system can sustain this disturbances or not, load shedding and the prevent ation off loss off Syncronys, so the substation controls is a flow off and exchange off energy. Therefore, we can disconnect to some roads which just called the load shooting in case off overloading to protect our generating power plants and prevent them from losing Syncronys. We can maintain the system Frequency was in targeted limits. What I mean by this is if we have, for example, frequency system frequency in Egypt, it is 50 hertz. So we can control our frequency between 50 to 50.5 as a maximum or 50 toe 49.5. And this is our limits. If the frequency exceeds this value or decrease balloons in 49.5 is in our substation contained devices which start working in order to maintain our frequency. Insides are targeted limits vaulted to control our substation contained devices which controls our voltage. We can reduce a very active powerful by compensation off reactive power habit changing off their transforms. So in order to control is a vaulted. You know that our generators generate B and a cure Active power Underactive boat soul. When's that demand for their active power increase? Zack, you increases. Our voters started to decrease. So we start to compensate. Is this reactive power by using can bestow banks which support or a supply que or reactive power? So our voltage was started to increase again. In the transformer we have tab changers. The Taba changes starts toe a changes. A number off turns off the transformer. A changing the number off Turness will cause a change inside the voltage. When we discuss the transformer, you will understand how heavy changing can change our voltage is the data transmission they a power line carrier for the purpose off network monitoring, control and protection. So our substation also can be used for that transmission. It can be used help in fault analysts and improvement in that area or field since our substation contained protection devices as relays, circuit breakers, cities and voltage transformer so they can help analysis off fault occurance And we can improve our protection and our reliability. So those are the function off the substations. 4. Classification of Substations: Now let's discuss Zack classifications off the substations. Number one Zack Classification. Based on the voltage levels, we have a different substations, a C substations or alternating current substations. We have a different types. According toe the voltage There is extra high voltage substation, extra high voltage substation, high voltage substation, medium voltage substation, low voltage substation and high voltage DC substations. So according toe the voltage 11 extra high voltage means voltage graters n 220 kilovolts 500 Gate of world, for example, 500 kilovolts, 750 kilovolt, 1000 to 200 kilovolts and so on. High voltage means any voltage graters n 66 kilovolt, medium voltage. Any vaulted? A greater than 11 kilovolt low voltage, Any voltage lower than living kilovolt. And of course, our director current or DC substations. So that is the first declassification. The second declassification based on our door or indoor, our substation can be our door under the open sky. It can be in a large area in ah, large open area or it can be indoor substation inside a building. So that's the difference between our door and indoors off station. We can classify our substation. According to their configuration, we have an air insulated our door substation or SF physics against insulated substation, the I s or composite substations having the combination off the above toe. So assembly the essay. Physics can be used in small areas. It can be most likely used, the insides there indoor substation. It uses that safe for 60 guests. But the substation or our door substations use air get insulated, and the year we have also a composite, which is a mixture between both off them, it contends. The combination off them. We have another classifications. Based on the application, we have a step up substation, which is used with generating substation or generating power plants as a generating voltage is low, for example, 3.3 kilovolts or 11 kilovolt and so on. So we have a low generating voltage. So we use that substation or the step off substation toe step, observe, vaulted. We have also sir, Primary Great Substation. It is created at a suitable load center along the primary transmission lines. So the primary grid substation it is along the primary transmission lines. We have a secondary substation. It is used according toe or along the secondary transmission lines. We have also their distribution substation. It is created. Where's the transmission line? Walter is stepped down. The supply voltage. So is a step up substation. It is used to step, observe, vaulted. Their primary and secondary great substations is is used. The ads, a primary transmission line and the second transmission line the distribution substation, which is used toe distribute the power. Therefore, we it is used to step down the voltage. So as the consumers A can or the customers, they can use the power. We have also the public supply and industrial substations, which is similar to the distribution substation, but it is used or created separately for each consumed. Supply and industrial substations are different from distribution that the solution step down the voltage itto their supply voltage 380 volt, for example. But our bulk and supply and industrial substations take at a higher voltage. We have also that mining substation. It needs a special design consideration because for the extra precaution for safety needed in the operation off electric supply. So some mining was a substation which is used in mining. Therefore, our mining requires electricity. Therefore, we will need a special substation for mining because it needs extra precautions for the safety. So those are the four classifications off the substations. 5. Relation between Voltage and Substations: Now let's discusses the relation between the voltage and substations, the primary substations, the received power from extra high voltage at 400 kilovolts, 220 kilovolts, 132 kilovolt and the step down one's a vaulted toe 60 60 kilovolts or Septus freakin world or 22 kilovolt. They are used. The force customers or load local requirement in case off the lewd and distance off the consumers and they are referred to was the extra high voltage substation. So primary substations, they are you step down. Is this voltages? 402 121 Answer. Tito In toeses values, they are used itto supply consumers such as the industrial consumers, and they are named as extra high voltage substations. There are secondary substations, which you receive power at 66 or 33 kilovolts and then stepped down toe 11 kilovolt the distribution substations. They receive power at 11 kilovolts and six table in 6.6 kilovolt, and stepped down to the voltage. Suitable for is a long Walter distribution purposes, normally at 415 vote. So now we learn it about two different classifications. Off the substations is a voltage and substations each type off the substations and cell voltages they are received from, and they transfers of altered, too. Now, let's see in the next video is their components on their construction off the substations. 6. Construction of Substation: the substation sports and equipments. There are Number one Our Door Equipment, which contends that incoming lines and outgoing electrical power lines they contains a passport. They also contains the transformers, or power transformers, supposed to insulate our answering insulators. The circuit breakers that isolators the Earth thing switches there. Surgery restores their cities or the current Transformers seventies or the voltage transformers contains a station nursing system also has overhead air Swire Children Against the Lightning Strokes. They consist off galvanized steel structures for towers and equipment supports. Number two is the main office building and number. Syriza's, which again, and control panel building number four. The Battery Room and D C distribution system Number five DC battery system and charging equipment. Number six, Zam mechanical, electrical and other auxiliaries, such as that firefighting system. That diesel generator. So the firefighting system, which is use the force their firefighting as it is showing from its name diesel generator. It is used as a but up generator or emergency generator to supplies the most important, most important auxiliary devices and equipment. So now we have seen the different components off our substation. Now let's discuss each off these components in details in the next videos 7. Electrical Power Transformer: number one is that transformer. So what is a transformer? The transformer. It is considered as one of the most important components in the entire power system. There are millions off transformers in our power system. It is considered as a backbone off support system due to its a used importance. So the transformer, it is used in electrical circuits. Why toe changes of waters off the electricity from flowing in the circuit? So it's the purpose is to change. The voltage is our to increase the voltage or decrease the voltage that increasing off the voltage is named as a step up decrease the voted it is named as a step down. So we have two types off transformers. We have the step up transformer and the step down transformer which is used to tow a step. Observe, vaulted or step down the voltage. The step up transformer is disused in substations, which is near toes are generating power Plant the step down transformer. It is used in their substations, near toes, a distribution and other types off substations. So how does it work now? Here is a single phase transformer, since our bowl system is as three faced system. So we work with as three phase supply. But here we will just explain their single first transformer end. It is the same as a Srini face. So we have here and iron core. And we have years of primary that second ring the primary which is connected to as a supply and secondary which is connected to the road. And we have here iron eliminations. Our core made off eliminations in order to decrease the A D losses. The primary has number off Turness NDB. The secondary has number off Turness in s we find is that using the transformer weekend changed the voltage. How you'll find that any be the number off turns off, sir, Primary over. The number off turns off the secondary is equal toe their voltage off the primary here or the supply over the voltage off the secondary. So by changing the number off, turn it off the transformer, we can. It changes their voltage off the primary and the vault off the secondary. So if we changed on, um but often is here, we can change the number off turn is Therefore we can change this ratio. Therefore the secondary will change we can using the table changing. Which means that we are changing the number off Turness we can. It changes, the voltage adds zeroed So in case off overloading which means that we are consuming more power. Therefore the voltage jewel started to decrease. Therefore, we will increase the number off Turness using is a tap changer in orderto returns a vaulted to its original value in case off over voltage which means that we having low consumption or power or low consumption of energy so we'll start to decrease. The number off turn is offset secondary in order to decrees a voltage again. So the transformer used the 42 things number or has two functions number on either toe a change The number off turn is a primary over secondary equals a primary off the secondary voltage or there primary current over the secondary current equal toe end the secondary Over In the primary, you will find that the issue here is the reverse so that step up the voltage will help us in decreasing the current. So again, again again in the B over in s if s increases over any being. Therefore, the voltage of secondary will increase. But here you will find that if N s increase sends a primary current increases or the secondary current starts to decrees. So what does it mean? It means that when we are increasing the voltage, we decrease the current and vice versa. So the transformer, it is usedto a step abs a voltage which will help us to decrease the current. Therefore, the as the current decrees. Therefore the losses will degrees. So that is the purpose off the transformer. It is very important electrical equipment and it's considered as the backbone off support system. You will find a whole course which I meet about the transformer. Now we will see here again the inducing metaphor which is here across the number off Turness, the number of turns or the V Albert over the embassy equals N s off any be the R word which is a V s or veto in this is a number of times off the secondary. Vien is a voltage officer primary and maybe is a number off donors off the primary. So according to this issue, we can change our voltage 8. Why do we Step up and Step down the Voltage ?: Now we have an important question. Why do we step up and step down the voltage? This is because the high voltages improve efficiency by reducing the hit close in some power lines. But high voltages are too dangerous for the use in home. So step down transformers are used. The looking to reduce the voltages to safe levels. So you will find that here the high voltage improves is the efficiency by reducing the heat close or losses. So how does a transformer reduce is that losses? As you know, that the parent power or generated s apparent power generating boys power plant equals toe three. But the black boys have voltage multiplied by the current cause I infi and adds a constant power or a constant s as the voltage increase the current will decrees which decreases our losses in the poor system as the losses are directly proportional with the current square multiplied boys a resistance off the line so the losses are decreased and also the hate is decreased. So that is a mean advantage off the transformer. They help but oh, inquiries a vaulted to improve the efficiency by Dick raisings. Our losses as a current it decreases and also we use it in the step down transformers in order to reduce the voltages to safe levels or the levels which can be used the at home, which is 180 votes, for example. So now we learn it about the transformer and 9. Lightening Arrester: Now let's discuss is a lightening arrest or so what is our lightening are. So it is an instrument that is yours. The incoming lines so that toe prevent is a high voltage from entering the mean station. So the high voltage is really dangerous or very dangerous towards the instruments used the service station, The instruments are very costly. So lightning arrester, czar, user toe prevent damage So that lightning Hristo does not let the lightening fall on the station. They just a bull it and ground 80 there's so it was a protector, our equipment and our substation from the lighting. They have an angle off 30 to 45 degree in the form off corn. So again, the lightening aristo to take their lighting which affords on the station and prevent it from falling on the station and the bullet and put ground a toes airs. So they take the dangerous high voltage. You know that the lightning has a voltage off nearly millions off values. Our transmission line has 500 killed. Walt, for example, is a maximum or 750 kilovolt. But this lightning's stroke or lightning comes from the sky, has a values off millions or voltage, so this value can be very dangerous towards the instruments. So he was a lighting guy. Restore toe arrest. Is this lightning and the bullet and ground eight toes? There's 10. Current and Potential Transformers: now let's discuss. Is that instrument transformers? Then it's trauma transformers. ER, used to transfers are voltage or current is the power line toe violence which are convenient for the operation off measuring instruments and relay protection devices. As really operates at low voltage 110 volts and the current and nearly life on birth, the line voltage is very high. For example, it has 220 killed, vote 60 60 kilovolts, 11 kilovolt and so on. So the current is in the range off hundreds or thousands off em bears. So we need devices to step down the voltage and current. So again simply the instrument transform. They are used toe transfers are line voltage 220 kilovolts 60 60 kilovolts living kilovolt into our low voltage as 100 thing kilovolt force protection the voices as really same with the current. We need cities or current transformers to step down the current from the 100 or thousands off EMS in tow. Five Amber which is suitable for really We use the current transformers and volts transformer toe decreases of voltage and the current the current transformers, As you see here, the current transformers, its principal for operation is very simple. Here we have us a 100 beer more week inside our conductor. Okay? And we have here Ah, holo conductor surrounding this conductor. Okay, Now we have here a quay which is around this whole Lochore. You know that in the current produces magnetic field. Therefore since 200 bear produces a magnetic field this magnetic field the cuts is is oil and therefore reduces induced the MF. Therefore it will reduce its current which is rife and there This issue depends on the type off the city. As you see here, our city is 100 bare toe five on bear so it convert is a 700 bear into five amber which is suitable for that protection. The voices as a relay here is another drawing for is this shape our mean primary conductor ? We have here a city or county transformer. Which convert is that that the primary into secondary or it changes 300 to 5 issue as you see here, here is a live image for it. You see, here's a conductor that which current and you'll see here the whole court around each of them and you will see here the connection towards the protection device The voltage transformer, the vault's transform assembly Step down the voltage so it is connected directly to our line. You see, here this line is 404,600 volt. But our our relate cannot sustain this amount of value. Can not whole disease amount of value? So we connected toe tool terminals off the line or single faces are line and the neutral off that line and we take it toe a number off Turness and we have ear iron. Accord is this is considered as a transformer. It is a really transformer. It has number often is here and the number of tennis here The number of tennis here is very high and the number of tennis here is very low. In order to step down the voltage from 4600 world to 115 vote here is another image. We have the current transformers. The potential transformer is the current transformer assembly that current bosses through there line or the route and we have here are coiled inside This one which transform into the secondary end of produces a small current here. Our primaries connected parent does allude here, connected toe serious with the road. It is therefore barrel and will take a sample off. It does a secondary. So that is the difference between the Volt transformer and the current transformer. They are used for protection and measurements. 11. Capacitor Voltage Transformer: in this video are goingto discusses a CA buster voltage transformer or CVT, the rest of voltage, transformer or city, or sees EEF. Eating is a transformer used in the power system to step down with the extra high voltages ignorance and provide a low voltage signal for metering. Our operating a protective really. So the difference between the capacitive Voltage transformer and the Norman Volz transformer is that this one is a single face and used for measuring the voltage in excess off 100 kilovolt where they use off, the volt transformer will be uneconomical. The water transformer will be ableto step down voltage in the range off the medium voltage or zero voltage. However, when our voltage or the voltage transmission lines for example 220 years world or 500 kilovolts and would like to measure Is this a vaulted? We will use capacitive voltage transformer or capacitor water transformer. So how does this come as to work? You'll see. Here's a high voltage terminal. Is that grounded terminal? As you see here, you'll see here at the best in cc one cabestan sissy toe. Then we're goingto take the voltage across See toe. We will use a transformer across. See two. Therefore, we are taking only the voltage across Ito. And we know that from knowing the vaulted here, we can know the voltage off the high voltage terminal. The voltage ear would be a Quito Xavi terminal or the high voltage German multiplied by C one over RC one glass. Cito, it is the same as resistive divider, but it is opposite to it. So we now have our lower voltage e we take apart off the voltage off the high voltage apart . And then we use a transformer to step down This vaulted and from knowing is this value we can deter mined the value off the high voltage terminal. So again, the difference between the cover story voltage transformer and the normal volts transformer is that the capacitive voltage transformers are single faces devices. He was there for measuring the voltage in excess off 100 kilo vote 12. Wave Trap: Now let's discuss another important component in the substation, which is a wave trap. As you see here in this image, this is our way of trip. So what is a wave trap? Ah, with Trip, it is the same as the power lying carrier Communication or P L. A. C C. It is used. It'll transmit communication and control information at the high frequency offers a power lines so the wave trip assembly used toe transmit communication and information at a high frequency over a power line. So we are transforming or transmitting our information using BLS. Ceasing is there. A wave trap also reduces the need for a separate emperor for communication between the substation. Instead of having an extra infra for communication, we can use the with trip across our transmission line in order to transmit the information at a high frequency. Also, the wife trap can be used to trap the unwanted waves, so that is a function off the wave trip. The with trip is simply gold is a power line career communication or pl sec. It is used a tow, transmit communication and control information at a high frequency. It also reduces the need for a separate emperor for communication number four. It is also used to trap the unwanted waves on the transmission lines. 13. Busbars: Now let's discuss another important part in our system, which is bus bars. The bus boards, as you see here, is this one. It is as defined as a conductor or group of conductors used for collecting the electrical power from the incoming Beefeaters and distribute them toe the outgoing feeder. So the benefit off suppose it is used to collect is a power and distribute them toe the outgoing feeders in another world. It is a type of electrical junction in which all incoming and outgoing electrical current mitts therefore the electrical passport collectors. The electrical power at one location, the electrical BuSpar is available in the rectangular shape is a cross sectional round and the many other ships Rectangular BuSpar is mostly used in power system. The copper and aluminium are used for the manufacturing for the electrical passport. Now let's see an example. We have here a passport. Okay, Riviera generator and honors our generator. The bus part, which is this one collected the power from the generator number one engine rated number two , as you see, is that the NATO number one is connected to this passport and this one is connected to the passport. This gives us the power to the passport, and this one gives us the power to the passport. Now we have some outgoing feeders. Off course there is a step down transformers or step up transformer, according to's, a location in the poor system circuit breakers before and after the transformer. For protection, we have here an isolator, which you are going to discuss in this course. Now you'll see that here is the collective power off the generators as he is electric passport, a conductor or group of conductors use the for collecting. Elected comparably are collecting the electrical power from the incoming feeders or the generators. And it is a collective power at one location, as you see here, and it gives us our boat power. So they're outgoing feeders. Now you will see here is that this is called a single line diagram. It represents a single face. So if we have a three face system which is commonly used in that our system, then we'll have a three passport. HC phase will be on one passport, their face a off each off. The generators are collected in on a bus bar, ends of his being off all of the generators are connected onto another passport and so on, So this is a benefit offs. A passport again supports part. It is used to tow collectors apart from the incoming feeders and distribute seven toes outgoing feeders. And it is also used a tow collectibles about at one location, and it is available in that rectangular shape. The cross sectional area and round that bus bar can be made from copper or aluminium. 14. Circuit Breakers and Relays: Now let's discuss a very important components in the power system or the protection for power system, which is the circuit breaker. And really so what does a circuit breaker? A circuit breaker? It is used to break the circuit. If any fault occurs in any of the instruments, as you know that the type of falters in the power system are single lying toe, ground fault or double line to ground fold or all lying toe line to ground or light line or three lines towards the ground. So it's a circuit breaker. It is used toe break the circuit, if any fault. Okay, so the circuit breaker acted as our muscles. They relate. Detectives are up normal conditions and the initiate corrective action as quickly as possible to protect is a power system. So really, it is a one which detectors are abnormal conditions, it detectives. That fault starts as a lyinto ground and initiate a corrective action and give order or a signal to the circuit. Breaker in orderto opens a second. So we have here toe important components, a circuit breaker which is actors as muscles, which breaks a circuit really, which actors as a brain it feels or detectives abnormal conditions and give on order toes. A circuit breaker toe opens a circuit they release are considered as the brain and circuit breakers are the muscles. The relays freezes up 40 conditions and send a signal to circuit breaker to operate. There are many types off the circuit breakers. Number one is the air circuit breaker. Number two was a vacuum circuit breaker number. SYRIZA is safer. Six. Circuit breaker number four, the oil circuit breaker and the minimum oil circuit breaker in another course. Who are going to discuss that protection off the world system? And we're going to discuss that the front of types off circuit breakers in details, off course, the relays off course. We we can discuss them in details toe. 15. Priniciple of Operation of Relay: it is a principle off operation off the relays. Number one. As you see here, we have here at current transformer or city. We have years, a circuit breaker, and we have here is a circuit Toby protected. Okay, so this circuit breaker it is used to protect this is lying. And we have era current transformer to step down the current. So the first thing the city stepped sounds a current from the line or the second Toby protected. And the tools? A relay queen. So the current flowing in here is a step down toe, a certain value, then the really quick if fault occurs, then the current would be very high. Therefore, they really will operate and gives Ah, high magnetic field. This magnetic field will produce a force which closes relay contacts after the relay contents are closed. Then this circuit will be energised as his ears hair at DC battery and then the trip coil would operate, which it produces are force, which will cause the circuit breaker toe opens a set. So again, what happens here? We have a circuit breaker which opens a circuit. We have the relay which is considered as the prey. The city transform is a current from high value into a lower value. Does a really Zinser really will start to toe operate? The relay will produce a force which closes the relay contacts. After the relay contacts is closed, then this circuit is energized. The battery would produce a current which flows through the trip. The trip coins in produces a force which opens the circuit breaker, but we have year and important definition a big up current. So what is a pickup current? The big up current off there, Really. It is a minimum current in the relay at which is a really started stow operate. If the current through very liquid is listens a big value Zinser really will not. Oh great. It's a currents rosary Liquid is more than the pick up Current really will start to toe operate. So again, where here's a really quick and a current the buses through it. OK, assume that they're really at five AM Bear will produce a force which is enough to close as a relay. Contacts now assumes that the current flowing so there really is listens A big cup which is for and bear now if we have a forum, Bears ends for amber will not. Will not produce enough force to close the relay contact so they really will not operate. If they really has a current more than five amber, then it will start. Oh, great. So again depends on the city ratio. For example, if we have here a city ratio off five over 1000 or 1000 over five, it means that if we have 1000 and bear here, then our five unbearable flew here. So in case off a fault, we assume that the fault is at 1000 and bear. So I win 1000 member or higher floor with throws a circuit that l A will start toe operate and closes a relay contacts. So they really here acted, adds a brain as he talked their current and the produce and action or a corrective action to close the really contacts. And since a circuit breaker started to overheat 16. Types of Relays according to Function: So what are the types off their release? There are types off relays according to's the function, the construction and the time characteristics. Now, according to the function, there is our current voltage and frequency. They open it if the import meets is a sitting. For example, if the current exceeds that big values inside really will operate. If the voltage increases beyond a certain value, since early will operate. If the voltage decreases below a certain values and they really will operate, it is a frequency is higher. Zen or lower than a certain values in the relay will operate. So here, according to the function, it is over current, really over or over. Walter generally on the voltage really over frequency relay under frequency, really according to the distance they're really uses a voltage and current toe measure the impedance to the fault. So the distance really, which is an important really. It is used to measure the in beading. So as you know that, that or the distance really is user toe protectors, a transmission lines so that really protecting a certain value or a certain distance off a transmission line. So this certain value or certain distance has a certain equivalent impedance. They really measures this impedance and deter mind if our photo cares or not, that the French are really the differential. It is used there to look at the imbalance between the in boots that the French release for examine it is user toe protected, their transformers. We have a primary, and we have a secondary. So is that really senses? There is a connection off the release as a primary, and the connection off relates at the secondary. The release, as a primary feels, is a current, and they really, as secondary feeds the current. If there is a difference between them due to an internal fault. Since the relay will operate, the differential is really an important really, and it is used to protect is a generators and transformers. It is common for power transformers and generators, and they can be used also for the transmission lines. So those are the types off. They relate in brief according to their function. Of course, in the course off the protection, we will start to discuss all of this in details 17. Types of Relays according to Construction: the types off relays. According to the construction number one, the Electromechanical. It consists off moving mechanical parts. Number two is ecstatic Elektronik. It convinces off electronic components such as his ability is the most fits. The Viars number three is a distant or microprocessor. The device may include additional features not available with electromechanical Elektronik release. It is mainly composed off logic gates, so the electromechanical it is as it looks from its name, electro and the mechanical. It consists off mechanical parts. Aesthetic elect running. It consists off electronics components. The digital it's consistence off digital components, or it is made off logic gates so that the star is the most important one of them, and it is the most expensive, as it can be used before several functions it confused as an over current over voltage at the same time. But the electromechanical and static abused the only for one function the problem off electromechanical. It needs regular maintenance aesthetic. All electronic is affected by Tim Britain that it is also affected by temperature. The electromechanical is sheep, but now, with the price off the static and it'll start is toe decreases with time. So those are the types off relays, according to the construction 18. Types of Relays according to Time Characteristics: the types off relays According to the time characteristics, Number one Zane is something it's really then instantaneous. Really. It operates as soon as operating value A. Smith. It means that the relay operates in a negligible type. In a very short, tight, the inverse of time relay the relay or the time of the really is inversely proportional to the current. So what does it mean? It means that if the current or the fourth the current increases since the time off, the relay toe operate starts to decrease. As a current increases the time off, our relay will start to decrease. They're inverse. Definite many mom time. Really. Then first definite time relay has a two functions number 18 orbits as an inverse as a beginning and then it operates as a definite So it is the first time eight operators and in verse as a current increases the time off. The release decreases after a certain value off current. It started store berate at with a definite time. As you see here is the difference between the time characteristics we have here is a different time characteristic plan. I DNT very inverse extreme. Liam's okay, now let's discuss each of them. You'll see that this is an emperor's Taib. Really, you will see is that as a current increases is a current and this is a time. As the current increases the time taken, boys are really starts to decrease. But for that inverse definite minimum time, it started as an inverse and then becomes a constant value. You will see here at different types off the inverse is there is a very inverse, extremely inverse. Is there a difference between them? You'll see that the nervous decreases fast. The slope of them is different. You will see is that at the same value of current. They're extremely amber. Stakes is a minimum pipe now. We discussed the types off the relays according to's at time characteristics. 19. Isolator: now, let's discuss. Is that our visa later? So what is an isolator it is used to protect is a transformer and other instruments in the line. It isolated extra voted through the ground. Thus, any extra voltage, you cannot enter the line. Zeisel later is used off their pass for protection. As we saw in the discussion off the bus, we saw House Isolator is put Zeisel eateries in stole the before and after a circuit breaker. Exaggerating switch isolates is a circuit at no load about a circuit breaker at normal loading conditions and fall to conditions. So there is a leading switch open and closes a circuit, but it only opens a circuit and close it at no load. But the circuit breaker can open the circuit and close. It adds that normal loading conditions when we have a lute, and that's a full two conditions. Now let's see a picture off size a little. See here. This is an isolated and this is the beginning and the end that first terminal and second term it This isa later opens. It is now the circuit is now opened. Now, when I have the later closes, then the circuit is closed, so assembly is a later isolated between the beginning and the end of circuit. The circuit is now open circuit. But when this isolator rotates, it'll closes on this one and then closes a circuit. Now let's see a video explaining our isolate. Now we will see here how an isolator operates. You will see that when it closes a circuit it produces an arc because due to a breakdown off the air between them. So this is how on Isolator works. It is really amazing to see houses. Instruments work. Okay, so it's now closing the circuit again. Uh, now this is how on earth is a little works. Now that is all for our video. 20. DC Power Supply: now, let's discuss is that D C Power supplies the D C ball supplies. It is any important auxiliary power supplies they see. Power is used in substation buildings, power lighting, heating and ventilation, and off course, a switchgear operation. The D C power is user. Toe feed is essential loads as circuit breakers tripped circuit the relays, skater system and communication equipment. So this is a benefit off the D C. Power supplies. It is just helps us to feed the essential loads. A circuit breaker, tripped circuit, two relays SCADA system and the communication equipment they see. Power is mainly used in the buildings power, the lighting, heating and ventilation. So if a photo cares, then using that easy power, we can fit our circuit breaker tripped circuit. As we discussed the before, when we discuss is a principle or for operation off the circuit breaker and really, we discussed that in that in the trip circuit we will have d c. Source because the sea is affected, Boy their voters. That's why we need a D. C. Power operates a circuit breaker trip circuit 21. Supply Line: Now, when this lecture, we're going to discuss their supply. Power lines. What is a supply Power line? Simply. The distribution substation is connected toe a sub transmission system. Very at least one supply line, which is often a primary feet. As you see here in this image, you will see here This is a part where our substation exist. This is the mean or the primary power lines. This is a secondary power lines, the second power lines in which it goes toe. The distribution network is a primary lions of power lines, which comes from our main power supply. You'll find the year you will find here they're bar where we have overhead transmission lines over headlines, which comes from our main power line into our substation and then goes out of the substation. So assembly the number one, which is this part is called is their primary power lines number 12 which is called the 2nd 3 power lines which goes to the distribution network. This part which comes from there, mean Boland or sir primary power lines on this part which is called the overhead lines, which is market as rate which goes toe there substation all of them are represented. The connection between the substation and off course, the mean bar lines and distribution NATO. So instead, distribution substation. We can have more, then one supply line. We can have one supplies the supply line like this one, or we can have more than one supply line in order to increase reliability. So I asked if one off the supply line has a problem or cut off. Therefore, the other supply line will is still feeding our little. So assemblies, a supply line or the primary power lines can be at a voltage, maybe at the high voltage. Extremely. I voted, for example, 1500 which is an ultra high voltage or a 750 kilovolt, or even has a 500 kilovolts, which is extra high voltage or even at a low voltage, like a medium voltage or our high voters like 122 kilovolts, 22 kilovolt or even at 11 kilovolts, 66 kilovolts 33 kilovolts. All of these values, according toe, the place off the substation from our name by power supply. You can have off course more than once of a station in our little hundreds off the substations because they are really Beneful toe benefit in orderto step up voltage or step down the voltage in orderto for distributes on all, increasing our voters so as to decrease the losses in the line. 22. Construction Of Underground Cables: Now we would like to discuss Zine definition off electrical conductor. So what is an electrical conductor? The conductor off course is a metal which allow is ical electrical current to flow. Or the Kanda Electrical conductor is the one which allows the message or the power transmission. And in our case, or in our electrical power system, we have two men types off electrical conductors. We have the underground or the underground cables, uses he or the underground cables and is the overhead transmission line. This is the conductor's, which are yours or the message off transmitting power from the engine. Reiter Dozy distribution area. Okay or from the generation told transmissions in distribution at substation, different substations. All of this the electrical power is transmitted using the conductor's for Z high voltage, we will use overhead transmission line and in medium voltage for the low voltage will use the underground kills. So, for our course, I want to give you some knowledge about the underground cables and the overhead transmission lines senses they are connected toe the electrical substation. So first we need to understand the underground kills. Here is an image for the underground cave. You will find that it's consisting off the conductor which allows the message off current or the one which carries the power. And then we have a layer off inspiration. Then any cheese, then another layer off z bidding. Then we have the armoring. Then we have finally BBC she's which is a serving area. So this in case off we have a conductor or a cable off only one court. Okay, Now, if we have a cable off ESRI Core which means that weekend they exist one s phase number a phrase number peel phase number C or you can say our ste OK, as would like so that three core or the multi core cable is like this consisting off a conductor has three conductors and insulation and a feeling between them and insulation between the three cables. Then another insulation outside, then our morning. Then finally z b Visine cheese. So we would like to understand what is the function off each off this parts? So beginning we have Z conductor conductor here, which is yours that transmit the power I want distributed power so the conductor can be made off aluminium or the cover. Since it is easy that has a high conductivity and economically accept it. The copper has ah higher conductivity and higher current capacity. Current carrying capacity Zanzi aluminium The cover conductive T for example 4 to 5 times the aluminium. Okay, so what does it mean? It means that for the same cross sectional area, we can have a lower area off cover. So for the same cross sectional area, it Zika bar has a smaller radio. What does it mean? It means that adds the same a cross section area, but higher current. Okay, So if we have, for example 500 bear for example, if this one is recover, then this one will be using aluminium. Okay, the cross sectional area off the copper is lower. Then z a cross sectional area off seen aluminium. And we can say that instead off saying same cross Canadia Toby more specific. The same current take our current carrying capacity or the same current. Okay, so for the same current, the cover will have a smaller area since it has ah higher conductivity. So we need a smaller amount off it. But at the same time, aluminium is much cheaper. Zan cover However, the connection between cables. It's simple in case off cover, but difficult in aluminium. Why? Because when we are trying to form a connection between this cables in case off aluminium aluminium oxide is form it. So that makes a very weak point in that connection. Okay, so let's is easy or the second component. Second, the component is the insulation. So what is the benefit off the insulation the insulation prevent is the electrical breakdown buys effect off electric field. Okay, so the insulation, but event Izzy or reduces the electric field reduced the Boise keep second thing in prevented the sermon breakdown. Boise effect off heat dissipation as you know that this conductor having a current and this current produces I square are RC power losses. And this power losses causes heat dissipation, which will cause the cable Toby hated. So the installation should wizard stand this amount of heat and the prevent dizzy cable from breaking down Sermanni. So what is the type off the insulating material on the installations? That first type is the dry paper, a dry paper wounded around dizzy cable. But this time has Lodi electric strengths due to the presence avoids inside the paper and at the same time it absorbs humidity, so this will increase that by electric strains. Second, the type is the paper oil, paper oil. We will take the dry paper and immerse it in oil. This helps store, fills the voids inside the dry paper and at the same time increases. It's a dialectic strength. 10 times is a dry paper that serve the type and forced type are the one which are commonly used that BBC or poorly van I'll write. And it has a maximum temperature, which can withstand 70 citizens Decree and the Cross Lincoln Bully Assulin, which is more expensive upto 90 solicitors degree both off that BBC and Crosslink get fully Selene used in low voltage cables which are used in the distribution area. Or that residential distribution 80. Now that third layer. Let's leave Z. She is now the let's see the armoring are mourning. Is this world okay? And it looks from its name, are willing is coming from our more What does it mean? It is used as a mechanical protection for the cables. It protected the cables mechanical and it made off aluminium or steel, and at the same time you have to remember that we bought here copper wires. Okay, inside this our morning. Why in orderto interrupt the magnetic circuit? So what does it mean? Okay, we have here a conductor on this conductor having a current passing through it. So is this current produces magnetic field and you as you're seeing magnetic field, and we have here a conductor varying the magnetic field. Since it is an easy so this varying magnetic field will cause and induce the meth inside. See our morning, which will cause the production off current and heat dissipation, which will cause the cable Toby heated. So, in order to a revised versatile, prevented this effect with simply both copper wires in order to reduce and use the myth in the opposite direction, which will cancel the effect off the magnetic field here forcefully are here is the bidding . What is the betting assembly? Yours? The toe protectors. E. She's from the armor. So we protect our seas from the armor. So since this part is forming off steel wires and covers also, it is made off cotton or BBC. Okay. Now, finally, we would like to understand what is the Luigi's the Leeches assembly, which is this part. What is used before it is used before are things he killed because, as you know, due to the presence off magnetic field, where theme the formation off the charges inside or the surface off the A cable. So in order to do this, we Earth's our cable by taking here a while. Does he ground in orderto disobeyed? Any charges? Because off course is this. Charges will cause hate dissipation, too. But the outer she's here, which is outside, is used or the serving she's is used toe protect dizzy cable against humidity. So this is the construction off the underground cables ends the type off the conductors used and using insulating parts and everything about the underground cables. 23. Construction Of Over Head Transmission Lines: now the second way off transmitting power is the overhead transmission lines which are most likely entering Z electrical substation. So what is easy transmission lines? All What is the material used in transforming power? You will see that here we have two hours and we have here an insulated with this party's incinerator. This one edged and it will be discussed. This part and we have here wires, wires and wires. Okay. Is this world's carries e electrical power? So we need told Scaasi insulators and Z material off the wire. So first we have at the front materials a c which means all aluminium conductor, or is it pure aluminium? This is the first type off the conductors used in transmitting power. This type has a high degree off corrosion resistance and also used in the railway and metro industries. Another type off conductors used Izzy a scene or the all aluminium alloy conductor. Alloy toe improves the mechanical and electrical characteristics. Z sir, the type is a C A. R or the aluminium conductor alloy reinforced, which means that it is an aluminium conductor Rainforest. The pie is the presence off alloy. This one have a great mechanical strength and the electrical conductivity is between 56 to 60%. The last one is a C. As our orders aluminium conductor steer rainforest. It is an aluminium but reinforced by this year. This type off conductors are much use for the long spans off transmission lines because this lines got high on science trends. So what does it mean? The long span. You'll see that this one is a tower and this one is another tower. And this is a team conductor and it has at something which is called Z sank. Okay, why do we do sag in order to allow when in winter when during the contraction, this one will be nearly a straight line? Okay, so we have toe Does this sec in order to prevent Is he cutting off wires in winter during contraction? That distance between them is called as pain. So the span for the long spans we use this type off conductors, aluminium, conductor, steel, rain forced. So in NZ overhead transmission lines, we can use the aluminium or the couple. There is another type off see materials a called the HDD copper, and this one has a conductivity upto 97%. So the aluminium conductors are more preferable than cover in overhead transmission line off courses are much cheaper and we have a long distance and there is another reasons. The first ones are much cheaper. As I said, second things er lighter in weight Zanzi cover. So they are light are so the power required will be a smaller tower at a slower strength. Our okay, but Z copper is heavy in weight, so we need a tower which can withstand Is this large weight? They have a larger diameters and cover. So what does it mean Means lower Corona effect. So I, as you know, if you don't know what is the Corona effect? This is a phenomena which occurs in transmission lines. You'll see that the conductor itself is producing is having an A C current, which produces an electric feed. And when this electric field exceeds the breakdown field off the air, which is Sertic in a vaulted per centimeter or as a maximum value wins this one, for example, conductor like here that's right, conduct or here like this and wins electric feed at a certain point in this region, for example, around Z conductor. This part is having an electric field. Great. Are Zanzi it? Breakdown electric feed off air. So what will happen here? We will have grown a current pulses which will cause a krone effect. This corona effect is having a power losses in transmission line number two. It will have an interference off or interference with communication lines or power lines, theme communication lines or radio interference. And does he produce an ozone gas or the information off all three? All of this happens during busy or due to the effect off the corona. So Z aluminium have a higher advantage by having a larger diameter. So it will have a lower corona effect. Senses e electrical breakdown or the electric field will decrease at a higher a radius. So now let's discuss Izzy types off the insulators off the overhead transmission lines. So let's see, we have here our tower and don't find here this one school dizzy insulator which she carries our conductors notice that it's carrying our conductor. Okay, so why do use insulator? This tower is connected to the ground. So if we connect this wire directly towards the tower, what will happen? The current coming from the power source will go through the tower and then goto the ground . So in this case, we will need insulator in orderto isolate between the the water and dizzied life part or the conductor. So you will find that this part is called Insulate. There are different types off insulators youth, but there are too many times. The 1st 1 is the pain cap and or depend time and 2nd 1 is a suspension time. So the 1st 1 which is that suspension type in this time you will find that here it is for Mitt off a group off discus separated off course from H other but connected by a string or fund. Your desk is in a desk, is in another disc and so on. So this one type, which is a suspension type incinerator, used the four high voltage greater than certain Cicely Kilovolt. It consists off a number off porcine discus connected in serious by metal links. In the form off a string saw the Ark desk desk that's connected in serious forming one suspensions drink. It can be made off glass or ceramic. The conductor is suspended. Ads e bottom off this a string, you'll find your answer. Bottom off this string, the conductor is suspended and Z as a direction is secure, the toes cross arm off the tower. Each unit or the desk, for example, it can. It is designed the full low voltage, so each desk, for example, again withstand 11 kilovolts as an example. According to's a manufacturer. So 4 11 kilovolt, this one can withstand 11 kilovolt. So if we both discus in cedars, we can increase the total number off or the total working voltage which you can with the stent. So, for example, if we have 12345678 and discuss, then it means that the voltage is that this one can was a stand off course at an efficiency off. 100% will be 88 kilovolt. Okay, this is that the maximum efficiency old z ideal case. But actually the efficiency off the string would be V face, which is here over n which is the number off discus, the maximum which is the voltage off one disc. This is that string efficiency off the suspension Strick, now another single would like toa say, for example, if the working vote 60 60 care of world at 100% efficiency we will need a six desk is connected in series in order to withstand or isolate or insulate between the tower and the life boats. So actually you will find that each off this discus is representing the boy aka past. Okay, so the problem is that we have here a group of capacitors and we have here this tower which is connected to the ground in actual or in real life do toe the reason so far, the electric material What is the electric material between the insulator and the tower? The electric simply Z atmosphere. So the atmosphere for Mazar die electric material So between them a capacitor would be formed and between each connection point gold is a stray capacitance. So what will happen in this case? You will find that the current from which is Aleka Jakarta busing So capacitance one. Then it would be divided here and here then homey, divided here and here. So the current here is not equal toe This one not equal toe this one. So in this case, the voltage supplied by capacitance one not equal toe capacitance to not equal toe capacitance. Three do toe different currents. So what will happen in this case? In this case, we have a different mitt methods as that first message is the grading off the capacitance. So we don't different values for the constants, or we do something which is called dizzy guard ring, where we connect a Z V feels like this. Then I connected this part here, forming a capacitance between them like, exists and cover since between them. So this will cancel the effect off the other contestants. This is one of the message or chewy, which is a used in azzi transmission lines. Okay, the second the time or zine type, which is you'll the 40 low voltage is the pen type in straight or find that we have here one element or one instigator. Okay, you cannot. You will find that they are not connected in Syria's only one insulate. And the wire is put here on the upper part of the growth for the conductor, as you see. So the 1st 1 was suspended at the lower part. But here it is been, and the upper part, this pen type in so little is used in transmission and distribution in case off the voltage lowers answer to stick your vote. But beyond disease artistic, you know what a zap and type is becoming toe bulky because you are using one insulator, and it means that they are on economic. So let's compare between these suspension time and depend. Type in straight the cost. The suspension pipe is more economical in case off the voltage graters answer to stick your vault. But spent type is more economical for the voltage. Eliza's answered three kilovolt. As we said before that, zip in type and ah, higher voltage will have or will be on economical end will be to bulk now in case off Z problem in suspension time orphan type or a damage in here or here, we will change only the damages units, the damage it disks. But for the pen type, we will change the holy on it, since it is only one in straight. The manufacturing for the special is easy because it was just about to discuss above each other. But for the pen, Trump is more complicated, since it is only one insulated, so the suspension type is off course, more flexible Zen's even type, since it is units about about the charges. The supported voltage suspension type can be any voltage by varying the number off units as we can change the number of units, as would like increases number of disks as we increased. Number of discuss the voltage supported will increase participant Time is limited. Maximum off 36 Gala Walt the Tower are much is carrying Z insulators and dizzy conductor and gets off. The suspension type will be longer and more expensive as well. As you see that that flexibility allows the conductor to swing the boys effect. Off went What's even time is short and cheap because it is one insulated only connected to , Is it? So this one has the advantage off Ben type is only in this sport and, of course, so Guess off. High voltage. Oh, no, said, seeking a what gets off lower vaulters lands and sort seeking of altars. And we'll use that pen So it's caused in this video Z overhead transmission lines and type off material used and the conductors used in this type off transmission 24. Comparison Between Underground Cables And Overhead Transmission Lines: In this video, we would like toa compare between the overhead transmission lines and cables. How, by giving busy advantages off the underground cables. Compare the tools, the overhead transmission lines. So what is the advantage is off Z cables. The first thing we have, the public safety and you know that our cables are both under the ground, but our towers or our transmission lines are expose A to Z wizard conditions such as E. Lightning, the storm and it's a so the overhead transmission lines are most likely, or the one which will have more falters. Such a short circuit or towers affording unlike a Z underground cables. So the transmission lines are ex was so the natural phenomena, such as frightening the storm, the rain and it's other. But the underground cables are under the ground, so they have less falters. Zanzi overhit transmission lines. Second thing is that our overhead transmission lines are exposed to Atrazine, the atmosphere or Z bearing in the public, So this overhead transmission line produced electric and the magnetic field, which interfere with communication lines. But the underground cable effect is very low. Since they are under the ground, they have this fault or Kiran's off the cables as they are buried in the ground, as we said before. But is that this advantage off the cave also compared the toe overhead transmission lines. Number one. The cables itself have a charging current due to the recent off higher capacitance because we have high insulating material with heart and I electric strengths, since our underground cable have the installation. But the overhead transmission line does not have any insulating material. It is exposed toe air, so the more insulation means that we have more capacitance. So the current or the wreckage a current or it's called the charging current in the capacitance is higher compared to tow the overhead transmission line. So this Causey is this limits the use off the cables in case off using it for higher voltage Elevens. Because as the Walter gee level increases, then we need more installation. So decree is the effect off electric field, which means more capacitance and the more charging current Z insulation cost. Remember that the underground cable are insulated by most commonly by BBC or cross linking police Selene, but the transmission lines are not having any installation. It is just exposed to air the size of the conductor in case off the underground cables is higher. Then off course is a size off the overhead transmission lines. Why? Because our cables have a lot off layers such as e insulation z BBC, she's Z bidding the armoring and so on. All of this layer increases the size of the conductor. Another thing is the erection or the digging off See conductors. It requires the cost off the digging. But overhead transmission lines are only requires towers the vaulted detection in the overhead transmission line Winner Fault Oh care, such as the cutting off any off transmission lines. It can be easily detected, however, in the underground cables. Since this cables are under the ground, it is very difficult toe detect accurately is the position off the fault? So we will use some kind off equipment, such as e maker, in order to detect Z a fault or the fault in a specific reason. Okay, And then, in this reason, we started digging in order to find where the fourth exactly so we can not detected default Exactly, and it is needs lots off equipment and difficult. So this are the advantages and sad bunch off the cable compared the to the overhead transmission line. It's 25. Types Of Circuit Breakers And Fuses: now, in this video, we would like to discuss something which is really important, which is the circuit breakers and diffuses, according toa there types and the comparison between them. But before we get in tow the circuit breakers, I would like you to give you an important definition, which is something which is called Z switchgear. So what is this? Which A gear and you will hear this word a lot. A za switchgear is a general term covering the primary Switching and interrupting the voices together was it's a control and regulating equipment. So this turn is related toe. Anything related to switching inside Z substations or inside our circuit. So, as an example, we have the power switching years, including the circuit breakers, since it is can turn on and off the circuit during normal conditions and faulty conditions . The disconnecting switch which can turn on and off the circuit. The city and DVT, which we discussed before the current transformer and voltage transformer Z relays, which is usedto detective default and or its considered as the brain which helped us a circuit breaker toe cut the circuit same as diffuse off course, including as a switch gear. So all of this representing switch again inside our sect. So now let's discuss Z circuit breakers and diffuse so that circuit breakers are used to disconnect and connect a circuit. Okay, during the normal conditions and the faulty conditions so circuit breakers can be divided according toe their voltage, it can be low voltage. Listen to kilovolt and the medium voltage upto 72 kilovolt and the high voltage circuit breakers more than 123 kilo vote and the circuit breakers that can be divided in tow. The type off, the interrupting medium. So what does it mean? It means that when we are switching on and off our electric arc this form it in the air gap . Okay, so we need toe them off or kill this electric arc. So we use and interrupting a medium such as air in order to distinguish Z three, the electrical arc, or we will sometimes s efforts X or Z. It's all fore hicks up right? And sometimes we use oil in sometimes use vacuum. This is a different medium off interruption. So there are different types, such as the moulded case, circuit breaker and the miniature circuit breakers, and they are used in the low voltage level. They are small circuit breakers, a small rating circuit breakers and we have air circuit breaker, vacuum, circuit breaker, oil circuit breaker and SF six circuit break and dizzy electrical power networks are protected and control the Y circuit breaker inside the electrical grid substation. So our our circuit breakers are mainly found inside the substation, and we can turn on and off the circuit breakers. Why use I usage off relay by controlling them inside our substation is that substations? The protection scheme itself is can be complex, protecting equipment and bus from off a Lord or ground the Earth's fault. So that relay is considered as the brain as we said before and the circuit breaker considered as the muscles which does the action. And we have our protection scheme. So, as an example is that circuit breakers will turn off after opening three microseconds or went see milliseconds Toby more specific on example point stream in the second and as a one after 10.6 72nd another one after one point. So many second, This is type off scheme called dizzy time grading skin, so their front of protection schemes are yours, and one are not going to discuss in this course. We are going to discuss them in our protection course. So the types off circuit breakers that 1st 1 is called dizzy miniature, and it is obvious from its name, Miniature means it is a mini meaning circuit breaker, a small circuit breaker and Amazon called Z molded case circuit breaker. Here is this Are does this. This is a three phase, and this one is a single fears. Both of them are circuit breakers, which is called that miniature circuit break. But this one is called Dizzy Molded Case Circuit breaker, and you see there is a difference between them. This one is just having a switch, which you can grows and open, and you'll find this switches at home. But this one, which is the more the case circuit breaker, have time characteristics where we can control the time in which our circuit breaker would be turned it on and off and ah, lot off characteristics to so that miniature circuit breaker has a current rating, Lizana 100 beer and the trip settings. OTA means e time Z current cannot be adjusted. Okay. It is just as if we have 40 Mbare circuit breaker. It will be cut off Wednesday. Current exceeds this value z a molded case circuit breaker which you like. This one has a rating, Liz in 1000. And bear is this is the maximum value Lizin 1000 and the trip setting, such as the time current can be adjusted easily. And f you notice that we said before that there is a time characteristics for that relays, which is inside the circuit breakers here. So that trip sittings the time. The type of the curves and so on can be controlled in case off the moulded case circuit breaker. Most of them are used mainly in the low voltage, only the second. The type is called Z large oil circuit breaker. So this is an image off how one oil circuit breaker looks like. So we have here at first determinant and another term and here representing our conductor. And this one is the another conductor, and between them is the circuit breaker. So to make it obvious for you, let's draw it. We have here outline and that circuit breaker between them like this OK, so this is representing. For example, phase number A and the circuit breaker is between them. So this one is going inside the circuit breaker and this one going out off circuit break. So this is similarly asked coming, then going out off circuit break. So this one is connected. So this one when this moving contact is here. Okay, So when this part is here, this part is this Incoming is connected. Does this one? And we have here Oil and Sisay Fix it. Contact and see Moving contact. Wen Zing Circuit breaker started. So disconnected the circuit when this part was here at the beginning like this. Then start is to move downward in orderto up in the circuit, you will find an electrical arc is for mitt Do toe the breakdown off air between them so the arc can be turned off, boys, a usage off oil. Okay, oil is used The ANSA and interrupting medium for this ark. So the advantages off the large old circuit breaker number one, it is efficient in arc interruption since oil is a high insulating material. But it's this advantages is fire hazards do toe the oil as you know that the ark the electrical arc reduces hate energy. So this hit energy transform Miss apart off the oil which is a hydrocarbon in tow. Hydrocarbon gases. So Z oil can cause a fire Hazards due to the presence of oil and the transformer senses are transformers are mentally having the oil transformers off course contain a tankful off oil . This is considered as a bomb before us. So the oil circuit breaker it's going is very dangerous for us and Z possibility or fire is very high due to the presence off oil which again have fire husbands. Second thing, we need a large amount oil in orderto extinct. This ark we need, of course, is a pubic replacement off oil. Because the ark due to the hit energy, it transforms the oil and toe hydrocarbon gases. So we need toe add the oil which Waas compensated. It has two types the large oil type like this one and minimum oil type in the minimum all time in a set off. Having or he like this we bought is the oil inside bombers and this promise of fire oil or bushes, oil injectors, oil en toes, iarc so the Ark will be extinct just very easily now. Another type off circuit breakers called Dizzy Vacuum Circuit breaker. We have here a circuit breaker. This one is called Dizzy Vacuum Circuit Breaker, and we have to contacts the fix it contact and the moving contact. When they are connected together, you'll find that the current entering from here as an example and going out off here. So when's the sport moves? Actually is there is a electrical our information. But however, in the vacuum like here, the electrical arc does not fall because there is no air. So what happens here? Zem This part and this part have a hope spots due to the presence off the potential difference between them. So the hot spot causes the metal verbalization and the produces electrons, which for miss AP Laz Moliere here, which is conducting and causing the presence off electric arc. So this this type off circuit breakers well cause Z electrical arc Toby extinct by the effect off condensation off this electrons which are produced, or the metal label which is produced, buys a usage off condensers inside Z, a vacuum circuit breaker. So the vacuum circuit breaker here is using a vacuum, as are interrupting medium Do you to its high die electric and effusive robots. Also a small contact. Travel your see that we have a small contact travel very small distance and which means that we have a less weight off moving parts, and they have a very long lifetime. And silent operation senses E. There is no gas is to be exposed or let our toothy atmosphere no explosion hazard, since it does not contain any and oil or any material which is explosive. Highest beat off the electric strengths recovery, and it can be used upto 230 kilovolt used in the high voltage Aries. The problem is, that is that this one does not contain any gases because it's called the vacuum. So if any damage happened inside it, then gases will go inside it and it cannot be rebelled, so it cannot be used for voltages above 36. Kilovolt is on economic, and it cannot be the bird in case off having any damage. Another type off circuit breakers is called the AARP last circuit breakers. So what does it do simply we have here the incoming, for example, exists and outgoing from another site. Okay, so the current here goes, like exists and what that would like to go to the other side. So we have here. Is he moving contact and to fix it? Contact wins. This part is, here is this part and this part are connected together so the current will flow normally but wins this part just moves down. Ward in orderto opens the circuit z our kiss form it. So in this case, when this one moves, we inject a blast or AARP last at, ah, high pressure and speed in order to turn off or extinct this type off are so simply when this one moves very high pressure and speed. Air flow is here and extinction this ark So the air plaster flows at a very high speed and pressure which helping arc interruption. But its advantages is a high noise, as the reasons off are very high speed and the pressure AARP lost having a very high noise . The s effort six circuit breakers. This type off breakers is very expensive, but it is very, very efficient in turning off the ark and instead off using air as an in interrupting media . We use s effort sex or the sulphur hexafluoride as an interrupting media. The cell for hex off right is a monster which feeds on the electrons, which is, ofcourse, electric artist form it off electrons and sf six is very hungry or off eating this electrons. So the sf six or the sulphur hexafluoride gas is a new alternative to air as an interrupting medium. SF six is our Carless, none toxic gas with a good sermon. Conductivity and Dennis. There are approximately five times that off air, so it is more Dennis is an air by five times. The principal off operation is similar to Z Air Plosser circuit breakers accepted that that it's safer six against is not discharged into the atmosphere. As you know that the AARP lost just turns off or interrupted Z arc and then this a charge towards the air. But the SF for sex is not the situation. Cozy atmosphere. It's advantage is number one. It has a sort Arcady aeration time. It is very efficient in clearing Z arc. Good insulating the prophets because it is very, very hungry off electrons. So it feeds on electrons and prevent is a formation off electric arc Silent operation as Z a safe sex is no decision. Order to the atmosphere. Unlike Z air plus circuit breakers as F six is chemically stable, nontoxic and inflammable. That s F six is less bulk is an airport off course more expensive? But the problem of the SF six is that despite not desist, goes into the atmosphere. But we will need to compensate some off the gases or some of the SF six, which WAAS used inside the arc ing or the Our King Samper or the interrupting medium. So how we can select our circuit breakers? We have a different time. So we have the Mitchell second breaker or the moulded case circuit breaker and the air circuit breaker minimum on Circuit Breaker vacuum, SF six and AARP Last circuit breaker. So, as an example, you'll find that their manager was, as we said before, Lizin, 100 bear. But the moulded case is less than 1000 and beer and they can boast of them come used at 400 to 600 volt air circuit breaker can have a voltage off from 400 to 11 kilovolts. This type off circuit breakers is. There are two types it break and Amazon, which is air plussed, this one having a voltage from 400 to 11 kilovolt NZ breaking capacity from 5 to 715 men of all time. What does this representing this? Representing the short circuit Travesty. When we devise this boy wrote Stream, What brought by Reliant Line. We can get the short circuit current, which you can interrupt the minimum on circuit breaker, having this range off the voltages, which means they confused at high voltage and having this break combusting. Same as for the vacuum your feels it will find that the vacuum is upto set a circular walk because off course, we said that more than that, it will be on economical and having this breaking conversed as have sex your friends that it can be used at any voltage in nearly at any voltage and having a very large combust and the air plus circuit breaker used off course seem as es f six at a high voltage and having a very large breaking calmest. So this is the types off circuit breakers and how to select the circuit breaker. According toe, the voltage and the short circuit level. Now we would like to discuss Z fuses. So the fuses here, which is this part, is used as a protection device, same as a circuit breaker. So it cuts is a circuit during short second. So they are used as an over current protection devices which protected the circuit and Dennis City Short sect. It opens circuit by cutting the fuse up link inside it. So this part as an example, which is this fuels inside it. There is a very small metal. Okay, wins this win. A short circuit current passes through this metal. Okay, this metal is the one which is connecting between this point and this point. So when's the short circuit current bosses? This government is very high, so it reduces a dissipation. I square are a very high heat dissipation. So this heat dissipation causes the cutting off this wild. So it becomes like this as an example, so it causes the production off air open sucked. But the problem is that when this one is Scott, it cannot get back. We have to replace this views after 40 clearing. So let's compare between the fuses and circuit breakers. The circuit breaker can be used repeatedly after four declaring, but diffuse can only be used once the circuit breakers walks on electro mechanical principles. But yours works on sermon properties as we remember that the fuse needs that I square are exceeds a certain value. But the circuit breakers works in electromechanical because it contained the really, which gives its signal, which depends on the magnetic field or electro magnetic field. Then the mechanical action Boise Circuit Breaker circuit breaker is off course, since it is used. A lot of times is expensive but fuses she because it can be used only ones. Circuit Breaker is quick to reset about those issues. Off course needs to be replaced manually, so we can after fault. We can trick or given accent a circuit breaker toe close immediately, but diffuse needs off course someone Togo and replace it Manuel. The circuit breakers are used in the protection off plants, the electrical power plants or factories, the electrical machines, dehydrating electrical machines, transformers and generators so circuit breakers will be found everywhere. The fuses are used in medium voltage applications, such as the protection off overhead transmission lines, the substations, the heavy industry and in low horsepower. So this is the difference between the circuit breakers and dizzy fuses and how to use them as a switch. 26. Types Of Switches In Power System And Substations: in this video, we are going to discuss Z switches. The switches assembly appear from its name. It is yours before switching or making a circuit on end off So the switches are used before isolating an electric circuit or a load interruption, which means the weekend adds connect and connect I load and the transferring surface or the electric service between the the front sources off supply, which means that we can transfer from the main power supply toe an altar needing power, surprise or toe an emergency power source and or we can transfer from emergency dozy men supply from cigarette. The types off the switch which are going to discuss is the isolating switch, the Lord brick switch and the 80 s or the automatic transfer switch. So what is the isolating switches? The isolating switch and you'll see a video in on other lecture will find a video for the isolating switch. The isolating switch is used toe make or break the current at no load. So again, it is a mechanical switching device used before making or breaking dizzy current at no load when there is no load present. But actually it is not also designed for making or breaking the current at full load or at Z folds so it is used in tow, open a circuit and the clothes a circuit in case no load present. But in case off the full load and falters, it is not designed to make or break this current. This means that it cannot switch in the prisons off a load, and they can be used on cannot be owes. The two opens the circuit during faults. It switches on and off at no load at the basins off. No Lord only its function is toe isolates the circuit. During ze maintenance, though, protected the labour against dizzy electricity present so simply the undulating switch appear from its name. Use the four isolation or protection off the labour in case off maintenance. You will find that during the operation, as you will see in the single line diagram, which I discuss in another video In this single line diagram, you'll find that we have isolating switches and circuit breakers so he gets off. We are closing our circuit. The isolating switch is the first toe be closed. Then finally, the circuit breaker. In order to make sure that there is no four to present. And guess off Z s short circuit or the patients off a fault is the circuit breaker opens the first, then it is the last that will be opened. So a general lord rule foresee switches is isolating switch. It is the first to be closed in any electric circuit and the last topi open during ze faults. This means that during photos that circuit breaker first clear default, then we can open So isolating Switch Wednesday Fourth is cleared. We can or the 1st 1 toe be closed. Izzy Isolating switch Zinzi Circuit break because the circuit breaker here acts as a safety against a Z short circuit, so we have to close it last in order to make sure that there is no fault to present. The second type is the load breaks which so what is the load brake Switch load bricks which assembly the mechanical switch. A device capable off making and breaking currents under normal no fault circuit conditions so it can cut or turn off the circuit at no load and turn on the circuit at for lewd. But it is mainly not designed. Toe clear defaults but sometimes sometimes it can be used a circuit breaker at the lower voltages, but it is used the four Z control and sometimes confused, a circuit breaker so appears from its name load breaks, which it is used to tow, break or cut off a load and connect a load so we can use it in order to control the loading off our network. So if you would like toa disconnect a group of fluids and connect approval floats, we can use the load breaks which, because it is designed the four opening and closing ad for lewd allude brake switch, or is which is made off air. Like this one. It is in the air can be modified to include an interrupter such as SF six or vacuum in. Orderto was the stand, the opening and closing for higher voltages and the current living's he served the time is the 80 s or the automatic transfer switch, and you will see that here, As you see, we have two sources and we have year our three phase and they will find that the three phase here are supplied having online from this power supply and from this power supply, okay. And you will find that the Lord brake switch controls, which this three phase are supplied from. So as an example, that automatic transfer switch always allude breaks which we have here. Our load, which is as three phase. And we have two sources here for examines the normal source for from cigarette and the emergency s or so from that you B s or the uninterruptible power supply or from the diesel generator and the automatic transfer switch transfer. But from this one toe, this one or the vice versa. So it it chooses what's one of the sources can be used. The toe feed zeroed so it can. In normal operation, it's electricity normal supply and in case off the fault or Z, a case off. No power from the grid. Zinzi switch will change from here. Does the emergency supply source and when it makes the shore that the power supply is return, it adds a nominal voltage and the frequency required. Then it will change back from this position or the emergency does the normal great power. This type off switch is primary use the four emergency and stand by power generation systems rated at 600 volt or lower. Such as, for example, if we have a hospital and we would like to make sure that sea power is not cut at any instant. So we have here the normal from sigret guests off the foetus or, in case of no power, we will transfer immediately. So that murdering source and in this case, it will be you bs, since it will be always supplying power. Okay, so this is an example off C A. T s. So we discussed in this video See the front pipes off switches which are used in our electrical power system and substation. 27. Importance Of Capacitor Banks In Power System: in this video, we would like to discuss a very important thing in the or very important equipment in our electrical power system. In substations and in every factory Zicam pastor packs. So the investor banks, simply our group off capacitors used the Soto supply reactive power. So again, you will find here to images for the This is a group off capacitors and we have here a group off ska pastors in our substation. So what is the benefit off the capacitor, which is connected toes egret in barrel off course. So what is the benefit off? Zika Bastogne? Simply The investor is your total supply reactive power to our great. So if we have our supply like this, then the cab Astor will be connected in a barrel like this. We have here our power, which is transmitted, and this cover store provide this air. Reactive power does a great the reactor power supply it Boise capacitor is used. A tow improves the voltage and improves the power factor and supplies a reactive power. Who are the biloute? So let's understand again, what is the benefit off? Zika pesto. So empower system is the power which we are consuming our consisting off parts the first time or the first power is the active power, which is use the tool. Provide a useful work, and the other one is the active power, or Q, which are used in our induct, Ince's and the contestants. Okay, so the power generated boy zem generator itself is called the S or the Apparent Power, which is consisting off active power. And they also one which is the active boat, for example, For running and induction motor, we will need active power as well as the active power. Soc Actor Bar is responsible for providing useful work inside our induction motor, which is used the fourth rotation off the electric mode and the act of power is provided or used before that magnet is ation off the field off the field, the winding inside the induction fourth, the electromagnetic converse. So as we remember that the principal off operation off any motor requires their presence off electric source, the braces off magnetic field or the electric field is transferred onto magnetic field and is a presence off Z magnetize a shin, which is provided by the field winding, and the reasons offer conducting material. All of this helps to produce our political electric machines. So the actor power wins are active power inside the machine increases beyond dessert's on value wins a demand off their active power increases beyond these ads on divine you orsa power which can be supplied by our generators. What will happen? Winds are active power increases the water just artist a drop and zero So the voltage starts to decrease Adds a load. So as you know that, that torque or the torque inside the induction motor the bendis on the voltage square. So the voltage adds elude or ads induction motor decreases do toes. I'm please in the reactor power demand. So what happens in this case? In this case, the talk starts to decrease new toe the voltage drop and dizzy motor starts toe withdraw more current because, as you know, that the power is equal to for the very own it system remote the blood, my eye. So when's the voltage increases or when divorce decreases the current starts toe increase In order to compensate the decrees involved it so the motor starts toe withdraw more current toe, provide the same desire, the talk so more current absorbent Bai's immortal. It means that in our line will be more voter drop as V equal. I'm not. Blood buys it. So more vaulter drop means that Zeevi started still decrease so current starts to increase and so on. So at a certain moment, there will be a chance off the power failure or blackout or something, which is called devoted to collapse due to the decrease off the voltage below a certain level, which it can cause all of the motors Toby turn it off by. It's a protection system. As an example, Boise under voltage relations or the under voltage circuit breakers, which is used toe, prevent Izzy Motor from withdrawing an extra current below or above its nominal value. We supply that extra active power in a sent off, taking this tractor power from the supply, which means more current ease. Absorb it. We can both the capacitor banks, which supplies zero active power and the load. So, as an example, let's here we have our generator and transmission line going through until here we have our loot, for example. So we have here are and the induct ance here. So we have said in total. So the current absorbent buys a supply causing higher forces drop. So the voltage at the load bus will starts to decrease. So more current absorb it and more vulture drop as here is the voltage drop is I'm out of blood buys it which means that the voltage ear will starts to decrease again. So in order to prevent it evolves to collapse, we will both here capacitor banks so Z generate oh will supply p and apart off the Q required by zero and the extra required. Que will be provided by Zika Pastor Bank like here. So the current here will be constant and extract you required is from Zika Buster Bank Absolute. So that means purpose off Providing cover store bank in case of power system is to supply reactive power to Z grant That act the power required a busy road and the audience told answer Receiver end and the capacitor banks are used to improve the power factor, which means that lower reactor power, which means that lower current and improved the power factor and lower losses lower voltage drop. So the capacitor bank is a very, very important advantage inside our power system and zk buster banks are called static var compensate or senses are compensating is ive are what, Ziva of our is the unit off the measurement off the reactive power. That's what called the far compensate or since they compensate their active power, require the pi zero. So this is the capacitor bank, and this is the importance off the capacitor bank. 28. Importance Of Ring Main Unit In Power System: in this video, we would like to discuss a very important part or a very important component inside our electrical power system. And you'll find this component in substations and everywhere. So what is it? It is the rain. The main unit. So what is the range? A main unit symbol. It's considered. There's a standard piece off switching gear in distribution system. It's consisting off past bars and consisting off load break switches, switches, isolating switches and circuit breaks. The passports are connected together toe formatting in order to increase the reliability and the flexibility off power system. So what does it mean? Here we have unit off that ring. Gamini on it. Okay. One ring gaming unit you will find here as three phase entering City of Hits City Face, you will find here a group off Serifis a group off Steve. Here's a group of three fees. So this one representing one unit. So what does it mean? Okay, let's ago Tosi figure here, which representing a group offering him in units. And what does it present? So we have here when the tour pine far, which is consisting from one generator here, and honors our generator here. This toe generators supply power toe this passport. Okay, so we have here incoming feeder and we have here outgoing. If either 20 This is our under or a transformer user to step down the voltage toe supply loads. And here's the last one is going toe another passport. So we have here one incoming one out, going toe, another passport and zeroed. So let's see, We have one incoming one hour going toe, another load and one outgoing dozy load here. So this representing one ringy mainly on it. So, as you see here, we have one incoming for examined as this one which representing the power supply and one going toe Another rink on one going toe Feed our load. This is an example off there in German unit now what will happens in this one connected toe ? Another ring gaming unit which is here. One incoming one out going toe, another ring and one out going toe, Another ring or another source. Then this one going toe. Another ring gaming unit and another ring gaming unit or toe another supply or an absolute . Okay, so we can have loot. We can have supply. We can have, um, another passport or this, uh, lying going toe, another passport and so on. So what is that? Each one of this is forming. Adding going from here isn't going to tow this one them from this one towards this one from this one or this one from this one toe. This one and the song. Now, what is the benefit off the string? What does it mean? You will find here we have a supply. We have another supply and we have year another supply from this water points. So an example. Let's see. We have here a load. Okay, this load, This one So is this one is supplying from this passport. This past bar is coming from another passport here, which is fit from Is this line this supply or from this supply? And at the same time, coming from another ring which is coming from another rink which is coming from this source or this to as our sources. So we'll find that if a fault, Okay, as an example, if a fault Oh, care here. So we can cut this line and our load will be still supplied from the other site. And this one will be cut off or will be switching off. Let's see another line. He will find that this one, for example it is supplied from here or from here. So if our fault ok is here, we will still supply our power from the other direction. So this or the rink by taking from one passport or toe another and from one passport toe another. This form is a rink which increases that reliability off the system and the flexibility of poor system. So if we would like toa door a maintenance for this ring, no problem. We can provide power from the other direction here or from other direction here and so on. So our system can be supplied from different sources at the front, a message. But if we talked about with a traditional system, for example, we will have your our supply feeding one line or one passport Isn't this passport is feeding a load here. So if a problem happened in this supply, then this power or this transformer will be turn it off and no power will be supplied. Dozy load. So what will happen if we have a rink? If we have a rink we can connect is this passport toe another passport which is fit from another line. So if a problem here, we can still provide power from the other legs and so on. So Ziering hell this to increase reliability off the power system. So I hope you understood the rain. Germany on it and the importance off Ringo Main Unit Emperor, assist the rain. German units also come in standard ratings off. It can have 11 22 or 33 kilovolts. So they appear in the medium voltage level 630 over 1250. And bear can have this rating or this rating and they can have a short circuit capacity off 21 kilo and bear four times three any second on. 29. Air Insulated Substation and Gas Insulated Substation: in this video are going to discuss the different types off substations according toe their configuration. So first, before we are goingto discusses air insulated substations and the guests insulated substations. Before that, we have to understand what is meant by insulation again. So assume that we have here electricity. Ok, this is called alive part which contains electricity. And this one also contains my world, which is electricity. This one. Okay, this one and this one between them and insulating the medium. This insulating medium as here is glass. This glass griffin prevented the transfer off electricity from here to here, or vice versa. So the usage off the losses to prevent is there or as an insulating medium, it insulate or isolates between this one and this one A 40 places this one with here. Then according to the voltage, we can break down this air and we can replace the air. Boy, it's physics or solve rxa fluoride social for hex. Our floor right has an insulating properties. Greater Zen, they're here. Okay, So in this video are going to discuss the difference between the air insulated substation and the gas insulated substation substations with. She was there air as an insulation between the electric parties in order to prevent a short circuit between them or between life port and the ground and their insulation using the essay for sex or sulphur hexafluoride. So what are the types Off substations according to configuration. So in this video, will discusses the air insulated substation or a ISS and gas insulated substation orgy. Yes. So, the first time, which is the air inserted substation you'll see here in this picture, you will see here a substation. This substation is in and in open air. Okay, this substation is in open air as you see here, or the components are exposed in, Ah, large area in here. Okay. And you see here all of the components used we use here air as an insulating medium between the electric components. Okay, now some properties off this E I s or the air insulate substation number one. We used air as a primary insulation medium. You will see here again. The air is used toe isolate between the left front electric components. Number two. It is popular where space constraints and environmental restrictions are not an issue. Okay, We use it in area in which we that we can take much is based as we would like and there is no space constraints that we don't have. We have much space and there is no environmental restrictions. We don't have much of allusions, our weather or climate. And so on another thing it is X supposedto environment. As you see here, it is not completely protected from electrical shock hazards. As you see it, it is exposed to air and they can be expose the tour there, lighting, for example, that this adventure off air insulated substation is number one. We are wasting larger areas. As you see here is there is no space constrains number two. It takes larger planning and execution. Time number city Regular maintenance is required since it is exposed to air insulation. Dettori Ation with time due toa pollutants. Since it is a supposedto as I environment. Therefore, it is exposed to the weather and climate conditions in the pollution. The last thing is larger dimensions your toe lower dialect experience off. Since it is a easily at the higher voltage, we can break down air more easily, so we will need large space or larger dimensions or large areas between the electric parts in orderto use air as insulating medium, I guess. Insulated substation or GREs we use, except for sex. Also for hexafluoride gas as insulating against between the electric components. It is used for voltages as 72.5 kilovolt 145 kilovolt 704 100 twin Taking a World the End move the equipments and circuit breakers, pas bars, isolators, current transformers of worlds, transformers and all of this Our field with essay for six because it is the insulating medium or the insulating gas between these components. The advantages off their safe sex It is non toxic man, flammable and stable. It has a very long lifetime. It is insulating properties nearly three times off. So if we need as based off air, then that Giants substation will require, for example, one over certain or one of our city off space required in air. Here is an image off the G I s. You'll see that it is an indoor and it is zegas insulated, always indoor. The air insulated is most off. The time is our door and rarely found inside or in door. So see that all of the components you can see here. The component as is air insulated substations. That incident substation, You will see the different Electrocomponents. However, here you will see that all components are field with as your yes or filled with except for six. Yes, it is used when we don't have sufficient space senses Joyce or the sulphur hexafluoride requires less space than air because it is high electric strength material therefore will need. It takes less space than air. So it is used when we don't have sufficient space. It has a difficult climate and ambient conditions. We use it when we have our environment or our door. It has a difficult climate or and ambient conditions and we will use surgery is because it is indoor and do not expose the toe. This conditions. It has higher reliability than air insulated substation. It is safety from electric hazard since it is indoor not exposed to toe air as our door or they are yes or the air insulated substations. It is more expensive than in I s essence who are using for 16 years. It is used indoor and area required 1/10 off the ordinary substations. It requires, however, high level off maintenance. It means that we will need high skin, the persona. So that is the difference between that bias and gas insulated substation or GI's. So again, when here insulated substation, we use air as insulating the medium door insulate between or isolate between the front electric components. We was it in open air or often area. We was a giant sword against insulate substations. In areas which we don't have sufficient spaces, we use it and it has higher abilities and, you know, it s however, it is more expensive. 30. Different BusBar Schemes of Substations: in this video are going toward discuss that the front bus bar schemes. So what is our passport schemes? Okay, when we are having or getting is a power and receiving it in tow our power station, we receive it on passports and then give it away or power which is going toe. The distribution is also from past bars. OK, so now let's see the different types of supplies part schemes in order to understand what does it mean? So we have here a single post scheme. We have men and bus main bus and transfer bus. We have double Bastable breaker. We have double boss Single breaker. We have also ring bus and breaker and health scheme. So now let's discuss each off them in this video. So the 1st 1 is a single pass. As you see here, this is called the single boss. Configuration or scheme? This is substation configuration consists off all circuits connected to a single bus. Okay, so we'll see that this horizontal line. Okay, this horizontal line is representing the passport. Okay, we have here this black box. Okay. Is this one and this one and this one, All of them represent a circuit breakers. This one. Okay, this is a switches off the circuit breaker. Okay, the behind it and four door after it. Okay, so we are receiving support from here above one circuit breaker. Then it supplies that single passport with the power, and then we take the album. Party was exists. Tow lines. Okay, so the failure off a single circuit breaker will also result in the outage off the entire boss. Okay. Assumes that the incoming circuit breaker, which is this one. Okay, this one, if this one goes away or having a failure, then no power will transfer toe their boss. Okay, so in this case, we have a low reliability. Okay? We don't have in way to supply power them Internets. Any circuit breaker requires a short down off the corresponding circuit or line. Okay. So if I start down here if we have a circuit breaker here as a failure and would like to replace it, therefore this line will not have any alternate. OK? Will not have any ways off supplying boat. So we were shot down this line. Their maintenance off the bus requires a complete shutdown. Those of us okay, so If we have a failure on this pass on the single pass, then we cannot supply any power. As you see, If we have a failure here, then we will not be able to supply any power. It is simplest and the least expensive fall configuration. Okay, or C years. There's one income circuit breaker, and to Howard going circuit breakers or two lines and only one single pass. So it is very sheep and simple. It has at least least on installation area, and it can be is leaks rented. It has the lowest reliability because a failure in one of them does not have any alternate way. Now, second type is the main bus and transfer possible. See, here we have in our system. Here we have two buses. I mean bus and the transfer. Plus, you will see that this line, this one on the left, is incoming Lying. Which supplies power. You'll see. We have a circuit breaker and circuit breaker and the and the price it could breaker we have here as which arise later. And our minds are sweets or isolator, and we have your transfer bus. Okay, so this is incoming line and this one is their outgoing line. So we have one more buses ed toe the single post substation scheme. We have years of transfer bus, which is more than two buses here, which is greater Senza single busk immature has only one bus the transfer buses energized by closings Isolator, switch through the transfer bus. Okay, so mainly, that power here comes from me from this line. Okay, And circuit breaker here is closed and this one is closed. So we are getting is about here and supplying this mean bus. And then we are taking the power from the members toe the Albert line here. Okay, so in case off a failure, for example, we have a failure on the members, so we cannot transfer any power to eat. So we close this eyes a little close the switch and closest, which is always supplies the power toe that transfer bus and we takes a power toe the Albert from the transfer bus in case off a failure, For example, in this circuit breaker, then we will close this one, nor money, so it will supply the main bus and then we will close our try circuit breaker in orderto trans fair power to transfer bus and then take their our boat from this. Isolate. Okay. Again. The power comes from here, ends and supplies this one and that comes from here. So it was our tie circuit breaker. And since this is a later is closed and we take that power and this type is more reliable sends a single bus. It is flexible in operation, and the mental ins it is has ah higher cost in due to the extra bus, then single bus. And that is extra switches such as regulators Now is a double boss double breaker scheme. You'll see here we have a tour bus, same as I mean on transfer bus. We have year one and two, and we have year two circuit breakers. The reverse one had one sick bricker and one isolate. And the Clippers. Okay, so now we have year the incoming and have your honors, our incoming and one Howard going. Okay, So what happens here? Normally that all of the circuit breakers are closed. Okay, We energize their means. One and demento, both off the double bus are energized. But in the mean and transfer on lee, the meanings and enjoys the but in case offer failure, we have turned on their transfer possible. So this tribe uses a tour buses and two breakers over circuit. The bosses are normally energized, and any circuit can be moved before maintenance without, with the outage off any gross bonding circuit. Okay, so in case off a failure here for examining this circuit breaker weekend supplies about here and the ticket from the second WAAS. Okay? And guess over circuit breaker here and here is the same and similar here. If we have a figure on the members, then all of the circuit breakers are open and we take all of the power from the second possible. In case off the failure off one of the two buses, all of the circuits can be fit from the other and isolating their field or the failed bus. It has the greatest service reliability but highest cost. This is game is used in the extra high voltage transmission substations or generating station and heavily loaded area. Now we have also the double bus single break or scheme. You will see here we have tour bus bars and we have here, for example, the incoming and one hour going and a bus. Sebesta is the one which connected. And they make a short circuit between the two passes as if they are one single bus. So we have here. Is that incoming? Okay. And we can supplies this passport and take Talbot from it. Or we can turn on both off tapas bars and take the power from them. So this substation Utah utilizing this configuration are supplied with store bosses. Since it is a double bus H, A circuit is equipped with a single breaker and is connected. Towboats, Boss, Using isolators, you'll see here we have as circuit breakers, this one and this one and this one. And we have here isolators, as you see here, this is relating switches. Our tiebreaker, which is this one. It connected between them in buses, and it is normally closed. Okay, so these two buses are being in advised boys, incoming line and we take the hour from them. If a fault in one buses in, we'll just, for example, a 14 members is in. This one will be an open circuit. This one will be an open circuit. And the ball story is an open circuit. So and this one is closed, and this one is closed to supply power to take the power from that second us suitable boss . Single Bricker, Skim off course. More expensive. Sends a single plus scheme. It requires more installations, presents a single boss configuration. Now, for that Inga bus you will see here that we have here in coming. This one is an incoming line with isolating switch another incoming line with isolating switch. This one supplies power tools. The passport you see here is that the bus bars are six analyzed. They are divided in sections and we have your breakers. Okay, So the incoming year and we take the power from here into a transformer, a step down transformer off course on Donna's are one here as a step down transformer. Okay, So what happens, Igor? What's the benefited? Provide this more reliability. How if a fault or cares here for examines, then we'll do. Is this switch and this switch and make it and always circuit? So we always relate this part. Okay. And as our power here is supplied from this one or from downward, Okay, it has here or here another example if we have a whole to here on this line, then we will make this an open circuit. This one and open circuit and this transformer will be supplied. From where? From this line. Okay, so the benefit off it, it gives us more reliability as there is no power. Shut down! Now we have the lost the scheme, which is breaker and half scheme. You'll see Here is that we have year as three circuit breakers one and two and three. Okay, we have a Syrian coming and three outgoing. We have also audible bus bar. Why? It is called the breaker on behalf. Because, okay, we have this line in coming. It has a breaker which is a member. Cough it. Okay. And this hour going has its own bricker, which is the one downward here. Okay, this breaker is in common between this incoming or this breaker and in the outgoing, also in common. So this one is called the one breaker, and this is 1/2 because it is common between the incoming and outgoing. Okay. And the normal operation is that all of the circuit breakers are closed. We supply power to this one, and the one world and we take power from them. This configuration uses toe men bosses post off each are normally energized with three breakers connected between their bosses. That breaker and have configuration is very flexible heist availability and more economical in comparison towards our double bus breaker. So those are the different configurations in the substations at different bosses schemes. Okay, so against a passport is the one which we receive our power and give aways. Okay, So just have to understands is suppose pars used toe collect the power from the incoming lines and give zap our to the front toe out going or the front outgoing lines, OK. 31. What Is IP Or Ingress Protection: in this video, we would like to discuss something which is called Dizzy. I be could for an electrical equipment or the ingress protection. So what is the I B or C ingress protection? You'll see that an electrical machine have a court as an example. When you look at a transformer, you'll find as an example are being let's write it. I be, for example, 54 Okay, so what does it mean? I b 54 in Z electrical equipment. So I be refer toa the Ingress Protection five here, representing the protection off the transformer against disease solids and the second the number number four, representing the degree off protection off the transformer against dizzy liquids. So, as an example, if this number is five, then it means that this transformer is duster protected and prevents Inglis off faster. Sufficient goes hard if you look at number four protectors against splashing water from any direction. So these two numbers representing the protection off the electrical equipment against Z, our type factors such as the solids such as e liquids on Sometimes there is an extra letter , and each of them refer to something such as high voltages devise or oil immersive and so on . So the first number Z protection and gonna sold scan have from 0 to 6, and for liquid from zero to it, zero means that we have no protection for our electrical equipment against disease. Wallet. One means that we can protect our electrical equipment against disease. Solid objects off 50 millimeter diameter and greater. So is the smallest object, which you can be prevented from passing through. The equipment is 50 millimeters. As the protection increases, you'll find that the diameter decreases. What does it mean? It means that it can protect itself more against dizzy small particles. So I do see a protected against solid objects off one millimeter diameter and great and five, which is more in a protection against dizzy particles, which is very small, such as tossed a protected and hear talk. Dustin's, which is the most or the highest level of protection against the sort now for the protection and Guinness's E liquids, such as water for zero, it has no protection, and Guinness liquid for one weekend protect against the vertical falling water drops from rain as an example, but here, protected against vertical falling drops with add agreed up to 15 degrees. As the protection increases, you will find that the amount of decrees that is this electrical device can or this electrical equipment can protect against increases number four. It means that protection against splashing water from any direction. Number five protectors against water jets from any angle. Number six, which is more higher against powerful water jets. Not only water jets, but powerful here. Number seven it protected against effect is off temporary immersion in water off a deficit between 15 centimeter and one meter for a time off 30 minutes. So, as an example, if the transformer has I be 57 it means that we can't existence former and immerse it in water for a dips between 15 centimeters and one meter for a maximum time off 30 minutes. If what it e protection is eight, it means that it is protected against the defectors off long periods off immersion. The maximum lips and duration is determined by the manufacturer itself, but it is the highest level off protection, so I be six. It it means that it is the highest level of protection against Z solids and again, a sissy liquid. So this is an important definition for electrical engineers in general, not related to substations only, but for any field in electrical power engineering. 32. Selection Of Busbars In Electrical Substation: in this video we would like to discuss is the selection off passports in substation. So previously we discussed dizzy types off passports, the different passport schemes, and now we would like Toa know how to select our passport. So as we remember toe, refresh your memory as you remember that the passports are used in electrical panel ports. Why don't connect Izzy incoming feeders from transmission lines as an example? Does the outgoing feeders as an example in distribution system, the underground kills. Okay, so passport is simply collected the power from the income feeders and distributes the power towards the outgoing features. It is yours. The toe connected the high voltage and the low voltage equipment. As we said before, bus bars are easy toe. Any stall, they don't need any cable trays like the cable trays in Z low voltage and they are cost effective, especially wins the ratings and distance increase. Okay, so how we can select our passports, this dependence on the front factors. The first thing is that the opposition off support our this passport in a horizontal position or in a vertical position in case we are installing them or is entirely over vertically. Okay, so we determines the possession. If it is horizontal or vertical, then we go to the catalogues, which contains easy horizontal passports and vertical passports. The currents that pass partial carrying in normal operation. So the passport should carry the current off circuit breaker or higher. Well, what? I mean the man circuit breaker off the substation. What I mean by this the largest the value of Z as value off circuit breaker. The bus partial carries this current in normal operation or even high the rated short circuit currents that the bus partial withstand in fort condition. So we have in the catalogue the rated current that the bus bar with his will withstand in case off the fault such as the three phase fault or the lying toe ground, the fault or lying to lying toe, ground fault and so on. The rated B current is that Zippo spars shall withstand in case off lighting off course again, the lighting off course. Our transmission lines and our equipment in Z air substations are exposed. The toe is the atmosphere and exposed toe lightning. So in this case, we have to make sure that our passports that can withstand this lighting during its short period. As you know that lighting it just happened for just microseconds. Okay, From 1.6 microseconds upto 50 microsecond, it's total duration. So we have to make sure that our passport can withstand dizzy lightning struck the temperature of the atmosphere and the heat dissipation off the components connected towards the passport. So we have to make sure that the when we are selecting the past bar we about the ambient temperature according toe the atmosphere surrounding zebras, bar and the heat and provided or dissipated by the components connect to tow the passport the i B as was weeds cause me before what is the meaning off I be the angriest protection off these which again, off the panel board containing see passport, the number off sections or bundles uber fears. So as you see that Z for the three fear system you can use the single core or a StoryCorps or, for example, are not recall multi core. It can be more than three and we can use bundle, which means that we have a group off conductors Bare face. Okay, group off single course a pair face this all of them form is abundant off conductors. Now, as an example for this, you'll see that here this is a part off a table obtained from a catalogue you'll find Here's a vertical passport. As an example, Type 72. This is in the catalogue. It'll and aim for is the cattle. You'll find one part off the bus pond 40 much blood by 10. This is the dimensions off the passport. 50 month blood by then and they will find 18 month blood by 10 and so on. And this is in case off one passport only. On this, in case off. One passport off 18 month blood by 10 to bus pars, three bus parts, 18 month blood biting and so on. So you will find that this BuSpar having some of them have RB 31 and I before one toe I b 54 having this information and this one having this information okay. And you'll find here This is the ambient temperature at which our passport will be installed according toe temperature, off atmosphere and the hate dissipation off the components. Now we will find that this was part, for example, at 35 solicitors degree can have a normal current off 1010 bear. Now, for the short circuit we have, I see that you and I being kill on bear. And in Colombia you will find that this BuSpar can withstand 50 kilo and bear office the I , C w and the 100 intent. I be So what is I c w and I be simply the icy W Is that short a circuit with the standard can't. This is a short circuit in which is a component or C BuSpar can withstand I B is the big short circuit with standard cons. A maximum current is that this equipment or this passport can withstand okay. And at the same time, it is the current That's the bus partial withstand in case off lightning. Okay, so that we have now our table and we know the condition so we can select it. Now let's see an example on how to select it. Calculates it frustrating for an air circuit breaker off 2500 bear. So this is the largest a circuit breaker connected to Z passport, and this representing the total current or the total current off the in normal operation and assuming that we need an I'll be off 54 and then I meant in Britain affords raises degree. So how we can solve something like this. So the first off all we know that we will select for our applications for our application or our installation area requires a vertical passport. Okay, so we obtain the vertical passport cattle look and then we need on i b 54 So let's go toe I b 54 which means this part. Now we need a current off 2500 beer. So let's see this passport at, of course, fourths Reasons degrees. So 40 seasons degree in this table I b 54 40 syriza's degree. Now let's see, we need 2500 beer or higher. This is 910 82,591 700 so none of them is acceptable. So in this case, we will not need only one BuSpar. We will need to pass powers. So we really chose Is this one or this one? Okay, if we chose this one, which is 50 month blood biting at 40 solutions degree. One of them withstands 1080 and bear. So let's see if assumes this one Zinser required the number off. Passport is the total current over the current capacity off one passport. So this will give us 2.3 1000 eighties from here from the table for the BuSpar. 50 month blood biting at a 40 solicitors degree. So we need to open three passports, which means we need three passports off this 15 month blood biting off course for as e barefaced. Okay, so we need three passports off this pair face. So they taught a number off prospers required would be nine passports, which is a larger number. So what, before assuming the 18 month blood by 10. If we assume 18 month blood by tendons are required, the number buffets 2500 which easy on bare capacity for the total rated current over the current off one pass far off eight and 80 at 40. Seizures degree is this current. So we'll need 1.57 Which means we will need to pass parts off this kind. And if we lose, this passport will need toe. But we will choose the smaller size off course, So we would need to off this. So if we look and see table when we are using at two passports off 18 month blood biting their current combusting at 40 cities degree and I be 54 will be 2500. Search so two bus pars bear fears off this type maximum current will be 2530. So this is the type of BuSpar will be used. Okay, so we need Topas powers off 18 months blood biting Bir face and the total number required will be six bus bars in our system. So this is how does electricity passport in substations? 33. Design of Substations: now when this video will discuss is that design off service stations, we can design our substations so its first general requirements in any substations. Number one, the installation and equipment must withstand electrical, mechanical and climatic influences outside. So we have to a study our side or the place in which we will put our substation according Toa there electrical, mechanical stresses and climatic influences at this site. So this is an important thing, which we have towboat in mind when we design our substations. That design should include number one. The purpose off the installation. Why we are strolling our substation. Is it toe supply an area with a specific demand or in orderto step down the voltage? Or it is used inside a factory in orderto or an industrial plant or industrial area in order to supply this area. So we take is a higher voltage. For example, 11 kilovolt or 22 you know, walked and step down in tow, 780 volt, for example, and number two customer requirements such as the poor quality, reliability and availability. So that Zion should include also that customers want what does what does the customer need as a power quality. It means that the bar quality problems is associated with for examples of voltage. It does a voltage have a war, Sinus or the wave, or does a voltage as a percentage off the harmonics in there, Voltage as a voltage must have fluctuations. How much fluctuations and so on. So the power quality is a great field. But we have in this thing we have toe identify what does the customer need and we just satisfy it? Another example is that if we require a power factor off buoyant line and we have here in our factory point it, then we will must install Cabestan banks is a capacitor. Banks is used toe, increase the voltage or supply reactive power in order to decrease the demand from the electric company and at the same time will improve the power factor off the company. So we will decrease our bill and increase our performance. Is that reliability? How much is our system is reliable. It means that What if a fault here the in as incoming electric power? What are we going to do? Is a factor. We're goingto be shot. That win or the factory will have another source or another supply or incoming line in order to keep the factory working in order to decrease as that shortage off power time. Okay, so the reliability means that Do we have one source that we have two sources? Do our Is our system reliable? Can it withstand? Is there transient actions, or can it withstand Is the switching accents which in large and small, switching large lords or switching large capacitor banks the availability? How much is our availability means that as our time in which our component equipment is available or electricity available so the total time through our year. So this is a different requirements which we have to keep in mind when designing our substations. The number is the ability to withstand transient conditions such as switching actions and so on, so that transient system must withstand or the substation must to withstand the transient conditions, which we thought, Does it mean transient transient? It means that the state, or when we are transferring from one in steady state, toe another between them. We have a condition called transient condition. Example for this when you are switching on a load or switching off and would a large would when we're switching Ah, large road then they're voltage will deep or decreases suddenly or trans Antony, you toe the increase off the route during that Is this Berio? Until generator starts toe, give us more power in orderto get the required power ends a voltage will return itto its nominal value. So during this this period is that voltage or our system will suffer from transient action . So again, on other examples of switching on or off buster banks switching on campus to banks will post the voltages suddenly because it supplies active our. So the Q is supplied toe that the power system or toe our factory in order to decrease the demand from that A full system. All of this causes are transient actions. That transient also means that and examiners are example if and by if a bus or and a transmission line goes out off service, then the other transmission line will be completely overloaded by all of the electricity. OK, since if we have a tour transmission line working in Baron, one of them goes out off service is in there. At this time, transformational line will have will be overloaded and we have also here Airtran's sent actions. Okay, all of this called the transient. So we have to design our substations and equipment to withstand that runs ent actions that safety off substations of personnel and the public example. The equipment must be Earth's it in order to prevent the floor off electricity, toe personnel or the public. Okay, that safety also unsettled with the circuit breakers circuit breakers. In case off our fault, we have toe turn off or a switch off their equipment gets off a photo prevent Is there to prevent jewel circuit or any damage? ITU's equipment or personnel number five Easy off extension and dim entrance maintenance. It means that we would like toa have to dough mental unstow our equipment. It must be easing toe does this extension in its instead off And guess off. We have an extension off. As the Lords, we added more area. Since the substation must be capable off supplying this, we have an extra area in orderto extend our substation or the toe give us the power required to this area. So all of this our concept, that which we have in mind and we'll see, what does the customer required? What does the area require? The influences and the site and so on. Steps off design number one. We have to collect data. We have number one toe. Make assumption. Based on existing consumption, we will see the consumption off the customers. And we see how how much needs a transformer needed, the load required as a voltages required, and so on Assess as a possible gross offload or for load forecasting. We need toe expect or make or do a lot for casting orderto expect how much our lord will increase in the future. Okay, so we need toe forecast or predict the future Lord Number city I'd in the finalist off connected loads and requirements OK, which is the same as the first step we need toe under the following the connected lords and the demand or the required electricity in orderto choose our equipment. Identify the Lord factor and diversity factor load factor represented every Jabbar over the maximum power that diversity factor representives help the lords are diverse provides the diversity means that if we have here a residential building and another one which is the administration building a factory All of this are the front loads. And between them there is a diversity factor. So if we say that we have 10 megawatt for four this then make a bolt and therefore this factory then make of all time bear four z a residential area and five mega volt and therefore administration or small apartments area All of this The total load is a submission multiplied by a factor. This factor is called the diversity factor which is decreases the demand for example 0.8. Okay, so we have toe identifies the diverse, defacto and with factor provide additional capacity for future Lord Gross about investment . Acosta will increase. Okay, again, we said that we have toe do load for casting in order to identify the future Lord Gross. So according to this, we will add additional capacity in order that door. That's why this future loomed, however, is the investment cost, of course will increase since that way, our adding additional capacity for future ludes. Number two was a selection off distribution voltage and transform aerating. Any substation must have a distribution voltage. For example, 11 kilovolts toe as 180 volt surround rating is a distribution toe the customers. Transformer rating depends on hell over how much or how many How many can make a vote and they're required in our area. So it was that his former, If you want to know what sort of transform money you can get to my own course for transformer and you will understand it from a to Z Okay for beginners off course. So if we receive and distribute as same boulders in there is no need of transformers for are having after transmission lines for example, a distribution, transmission line or sub transmission lines which is a living kilovolt. Then we wait and we distribute living killed again. Then we don't need for transformer as a transformer is used toe step up voltage or step down the voltage. If you are receiving at the higher voltages then we will have a transformer in order to step down the voltage example, living kilovolt which is receiving voltage and transmit or the distributed voltage will be 380 world Then we would need a transformer in orderto stepped down this voltage where will use TLC or the on load tap changer in order to change the number off Turness in order to control them outward voltage or the transmitted voltage. Okay, so in case off the demand increases Senza voltage or started to decrease. So use that tap changer to inquiries. Number off turns off the second inning so we can step up the voltage again so that although temperature and then I will find it. Also, in my own course, the former size wants to be selected according to the maximum expected load and the possibility off future extensions. So this is really logic. We need toe choose a transformer. According toe, they're expected. Load the maximum it and we have to consider possibility or future expansions the different available ratings for substation transformers we have here at 25 kilovolt and their 50 kilovolts bear 102 154 100 concerning the authority at 101,000 kilovolts number one, mega 1.25 mega 1.6 and mangled worked and there to make of all time. So this is a rated powers and you have to remember this because you are going toe use it and an example Now, primary voltage, which is receiving one, is 67.2 to 10 12 20 to 24 to 1.5 and so on their second revolted, surrounded 80 world or 400 world most likely 404 100 vault in order to Is that the different is the difference between them Is that 20 volt, which is yours? The four voltage drop. Okay, Now we have to choose that bus configuration which we are goingto discuss in another video which is a single bus configuration or double bus double breaker breaker on behalf. And so on. All of this, their selection off the substation equipment. We have to select appropriate suitable equipment according to the rating off transformer and receiving voltage and mystery rooted voltage, we will have to choose a rating of circuit breakers. The rating office s which this connectors or robotic switches They're rating off isolators their characteristic of the voltage transformer or diabetes and current transformers. And we have to ensure that we have a spare equipment such as a spare circuit breakers spare future transformers and feeders. In case off any failure in this equipment, we just take this equipment and the boat another one we have here animals are seeing, which is for factories we have toe make duplication off. Everything you'll see is that if we have here a factory and for example, we have here motor, which is 116 kill Want. Okay, so this one must have with public it. And two sources you will see is that this is the 1st 1 which is a transformer is a source of number one. This one is another source and you will see here between them as they pass cobbler which is used to as which one and switches as a one off and so on. Okay, so now we will see it. A transformer, which is another one, which is another transformer which is identical to it. So we have been here a duplication off the transformer and we have here answered release. He won radio relay off circuit breaker one and the really off circuit breaker to this is also add application. We have a relay and circuit breaker here. Andan also really in circuit breaker here we have two sources with its components, which is a publication off the protection devices. Okay, we will see here the different sections circuit breaker here after the transformer on Donaldson Circuit breaker. After all sounds former we have here are all source. And we have here a bus coupler in order to switch on or off. If it is, switch it on. Okay. Is in this one. Have a failure, for example. And this one were start to supply this one. So one of them is essential and another one is used as an emergency. Okay, this system is expensive, but it is more flexible for operation. Now. We have also there a substation layout. We have to make sure that we have clearance airsick clearance clearance between the life parts and structures. We have a face clearance between different faces in order to prevent this whole circuit between them lying toe lying toe around or lying toe line and so on. Eyes relating clearance clearance between Zarins. Later contacts. Now let's have an example. Consider that you would like to choose a transformer to supply power to affect three, which requires a maximum of 270. Dealer vote off power. Enter 400 volt, owns a local site, and the no expansion is required. Okay, so the power will be provided by connecting the factory toe 330 33 Kilovolt Walter. No. Mega Volt is a certain secular world. Only it shows that transformer required. Okay, so we have here at 170 kilovolt and bear, which is I require the power. Okay, we have a 404 100 wall tones and water in sight and said this cynical of water on the high voter side. Now let's say the turn again. Toes, transformer ratings. Okay, Now we have 217 gala world, so the nearest one is 250 which is lower sense of the month. So we are not going to use it. We're going to choose their 400 kilowatt and bear, which is the closest one to our demand. We have asserted city as a primary voltage and the secondary is 400. Very simple example and very simple thing. Right, you will see is that final 400 kilovolts, which is the closest to toes at 170 kg of want. And there is no expansion concerti seeking work, which is a primary and 400 volt, which is a second. That's all about designing off the sub stations 34. Single Line Diagram Of 66 To 11KV Substation : in this video, we are going toe. Discuss Z s L. D Orsi single line diagram off a substation. So we have here an image which is design for an electrical substation off 66 toe 11 kilovolt. As you know that or as you remember from our course that we said, is that the substation can be step up or step down the vaulted. So this substation is a step down substation. They are used toe step down from 66 kilovolt coming the from two different sources. It can be from an overhead transmission lines, or it can be from underground cables. So, for example, here's the substation 66/11. The Argos toe or convert, is E 66 kilovolt towards the 11 kilovolt as an out. So let's this easy construction here or the single line diagram. First, we have here each off this lines, which is his part, and this one this one is an overhit transmission line off a 66 kilovolt. This is another overhead transmission line 66 kilovolt. They can be from the same source or two different sources. Here we have Z underground cables, okay. And this one is another underground cable. This one can be from the same source or a to the front sources. So this one used to provide a 66 kilovolt. And this one too. Toe double passport, double passport Here, B one and B two. Since we have a passport, it is called a double BuSpar. And it is sexualized because you will find years at sea. BuSpar is divided into different segments will find this part is alone and this party's alone and the sport. Okay, so let's see easy construction off each part. Or the benefit of which Barto as remember overhead transmission line is exposed toe lightning. So we have here at lightning arrester. Okay, Made off. Hold the gap, for example. It is used itto protect our transmission lines from the lightning. Z takes the lightning, and but it was the ground. So this is the 1st 2 components the lightening a restaurant. Second component is the grounding switch. Okay, what is the benefit? Off the ground switch. When we turn it on and off course, everything is off. The circuit breaker here is off The switch. Isolating switch here is off. The grounding switch takes all of the charges inside the transmission line and ground it. Okay. It is usedto disa George. Any available charges in the transmission line? Why do we does this in order to in case off maintenance off the transmission lines. Okay, so we have to make sure that no charges is available on the transmission lines, So that is a benefit off the ground switch. There is also the isolating switch this Isa let's which is yours before switching on and off. And of course, it's which is on and off at new loot. Okay, then we have this part, which is the circuit breaker circuit breaker is used, the 40 protection against shorts irked. Okay, we would like to protect our transmission line or our component off against short circuit by the usage off circuit breakers, as circuit breakers used to protect against short circuit which is made from ze single line to ground falters, lying to line to ground fault is symmetrical or asymmetrical folds and so on, so that so That is a benefit off the circuit breaker as we remember that the circuit breaker is acting as the muscles, the one which is which on and off during shorts act Here we have this simple which represented our current transformer. The current transformer is used for measurement and protection. It is used to step down the current inside the circuit in orderto measures, the actual value off the current passing or absorbed by our line. Okay, is the current transformer is connected toe the relay which is the brain which controls Izzy Circuit breaker. So when Z relay senses that the current exceeds easy big current, the circuit breaker starts toe a switch off our circuit. Then we have here another eyes ratings which will find that our single and album is full off Isolating switcher toe switch on and off Z component. For example, If we switch on this part, then we are connecting this line or the overhead transmission line told. Was he passport number two. So it supplies power toe passport number two only if we close this switch, then it supplies power tothis passport too. Okay, so when this one is off on and this one is on Zinzi overhead, transmission line is giving power toe passport number two and passport number one similarly here and of course, affords the underground cable they can be incoming cables. They are providing power, Dozy passport or it can be outgoing. They are taking the power from the passport and going out from the substation. Okay, as a 66 kilovolt, too. Now, another thing you'll find that we have here this simple, represented see potential transformer, which is used also for protection and a voltage measurements. You know that the potential transformer, as we discussed, used the four step down the voltage inside the circuit. In orderto measure, the actual value of voltage and we have here is a simple So what you have used Isolating switch, grounding, switch, circuit breaker, current transformer potential transformer and dizzy lightening arrested. All of these components are said to be they are called what they are called. Switch again, switch again. Any component which is involved in the switching actions, the isolating switch is involved in switching on and off the circuit. Groundings, which is to circuit breaker is yours. It'll switch off the circuit during a short circuit current transformer used for measurement which leads in the end of for switching on and off, same as the potential transformer, and is a lightning arrester which it takes Z lightening towards the ground. Another thing You will find that our passport is sectional ized. What does it mean? It means that this part or the overhead transmission lines this one and this one is providing power to assist two passports. OK, then we take from this passport toe, provide some roads and this toe passport is providing toeses and coming or tothis underground cables provide power. Also tothis passport one under to tow this part only And this one tothis part only if we have an error or to be more specific, not called Arab A fault in this cables. Okay, we have here a problem and would like Toa provide power tothis part okay and the or tothis passport. So in order to do this, we will have to switch off or switch on this isolating switches toe connected this to some passports. Therefore the power provided by this component is through this passport and the tool is this double passport. Okay, so the benefit off this it separates between this part and this part and in case off, if we have a falters and would like to give the loads here operating, then we will connect. Is this two passports in order to provide power to them. The connection between them is dump I. Something which is called a past couple pass cobbler is also a circuit breaker and will understand more about the past couple of in the part we will discuss the 11 toast 180 volt substation. So what happens after this? We take power from C passport, this passports and this passport. Okay. And we have also current transformer circuit breakers. And this power is a 66 kilovolt. It goes toe a transformer 66/11 kilovolt transformer in order to step down the voltage which is the benefit off our substation now is the living kilovolt here is providing power toe another passport. This passport is 11 kilovolts passport. And you see now that this transformer gives the power toe this passport and this transformer gives a part of this BuSpar. This transformer gives tothis pass bar and this one does this passport and we'll find something interesting. You will find that here we have a bus coupler we have here on other past couple and on Assad Boscap and you'll find here air cables. Each off them is 11 kilovolt going toe substation 11 kilovolt or going into a transformer 11 Toaster 180. Vote as we'll see. So we'll find that each off this which is 11 kilovolt going toe as easing, which you are going to discuss in the next a slight. But now you will find that this transformer is supplying power. Tothis component Okay. And this transformer is supplying power tothis part and this transformer providing power toe this part and this transformer provide power tothis part Ok, of course, with his own off its power blew it. Okay, All the elements here by exists So this transformer provides power to all of this until z pass coupler, this one provides power tothis between it and pass cobbler. This one provides tothis four lines. This one provides power to all of this Now in case off any off them having afford this one having a fault or something, then we will switch off our circuit breaker or make it an open circuit. Zen Z transformer will supply power to all of this. Okay, so the past couple are same as here Instead, if we have a faulty here, we can connect to this passport by bus coupler in order to provide power does a passport. Now we will find an additional sing. We said that here we have a 66 to 11 kilovolts 66 to 11 kilowatt and sing going through cables. As we said before. But you will find something you will find that we have here. And additional transformers 11 Toaster 180. Vote. So what does it does? This one is called an auxiliary transformer which will provide his answer 180 vault, which is our lying toe line. Voltage! What is the benefit Off this transformer or this transformer? They provide us your 180 volt dozy loads. Okay, Is the Lord's off the substation itself? The substation itself has our lighting. It has a components which works on interest. E all of this needs power. So where we can get our power? We simply take one of these cables and one of these cables here and go and provide it toe a transformer, Step down transformer to provide power which is suitable for our substation itself. Okay, so we discussed in this single line diagrams at 66 to 11 kilowatt. So if we look at this one or this part Azeem Each off. This is E Albert from Z 11 kilovolts cables or from the 11 kilovolts substation. They are here from 66 to 11 Kilovolts substation. Where does the 11 kilovolts to go? They don't goto a substation. Okay, They goto a transform Our transformers 11 toaster 180 vote as they have definition called dizzy kiosk. Okay, it is kiosk as this represented Z transformers, which is us. Your 182 11 killed Walter 280 vote. So this transformer is a step down. Transformers 311 kilovolt to 780 evolved. Okay, so this is another step down transformer. So they live in kilovolts cables, go here and support or provide power toe a passport called the distribution point. Okay, this passport, what does it do? It collectors the power and then distribute this part. So that's why it's called a distribution point. So this BuSpar, which is the 11 kilovolt, and this one is the cables. This is at 11 kilovolts cable, and this one is a living kilovolt. And this one too. So this sources are from the same substation. Okay. Is this one are from the same substation and this are from another substation. Okay, so at, in orderto separate between these two substations we bought here are past couple. Okay, this one is a tool. How it off? Three. Okay, so what does it mean? It means that if this one is working and this one is working, then this bus coupler is off. It is with this one. And this one two out of three. OK, we have 123 on Lee two are working, which is he? Income cables here and incoming cables here. And guess if we have a fault here, for example, afford in this part. So we turn off our circuit breakers or our circuit breakers will cut off the circuit. And then this past couple er will be on in orderto allows the power toe flow here and the floor here. Okay, that's why this one and this one will work, and this one is off. So it say toe out off three toe are working out off a three components. Now, if we look at this diagram also, you will find here we have this. Cables are providing power tools that living kilovolt is informs the BuSpar we take 11 and provide it toe a passport. Okay, this passport supplying a transformer and 11 toaster 180 volt. Okay. And from the same passport, we take a point. Then we go to the next one them from this one toe This one them from this one toe This one them from this one toe. This one and so on. Okay, so what are we doing here? We are taking the manpower living kilovolt and provided toe 1st 1 then from the first pass bar. We take it to the 2nd 1 and so on. So you will find that here and connecting off course. All of this here too. Okay. Forming alone. Okay, so it finds that this is this and this one is connected. Toe this one and so on. And between them, isolating switch. All of this is forming a loop. This is what's called a rain game in on it. But also toe mention that you will find here is that this one and this one one of them are off. Why in orderto prevent easy connection off this substation with this substation? Okay, so what is the benefit off? Zero If we are not connecting between them. Then what is the benefit? The benefit is simply lives. This. Assume that we have a faulty here. Okay, so this circuit breakers here will act and turn off this line, Okay, due to the presence over fold, and this isolating switch will be off. Okay, so we would like toa provide power through this part. Okay, so in order to provide power toe that three and four, we provide power from five going through four and three held by closing this switches. Okay, so the benefit off it is that in case off, we have a fault here, and we cannot supply power in this direction. Then we can supply power toe the Lord's here in this direction. Okay, so, uh, the benefit is that if we have here also our fault and we isolated default here, OK, we connected the switch and this one after the action off the circuit break. So we connect Izzy for provide power from this direction to number two and provide bar from here. Toe number Serie and between them here is isolated. Okay, so that is what's called a loop. You can say that here as this party can be from the same substation or the load can from here and going toe another distribution point. OK, it is not the same point. It can be the same point and it can be at the front point. But anyway, it goes from a distribution point to another. It's called a loop, okay, because we can supply power in this direction or supply power from the other direction in case off the faults. 35. Extra Images: here is another shape for the passports. And here is another shape for the lightning. A restaurants, as we said before, which is used to catch. Is there lightning or the outside light surge voltages or even the case off the transient and other purpose? Now he resembles our image of for an oil immerse circuit breaker, this one. And, as we said before this oil immersive circuit breaker, just make our circuit on with circuiting case off the over current or as a protection for our power system.