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Hello learner, in Today article we will discuss about the components of electrical substation with their functions.
In this blog post i am explaining electrical substation components in same / easy Word to understand.
For finding the perfect explanation of these topics we have to read many books and lot of research on the website / YouTube to gain information.
Don't worry I had already done complete research on this topic. And i am ensure after complete read this blog post, You won't need to go anywhere.
What is electrical substation?
In the present time electricity is basic requirements for a human being, thus for proper supply of electrical energy it's necessary to control the electrical power.
The arrangement of electrical equipment in proper manner for which used to control / change some characteristics of electrical supply is called as an electrical substation.
There are various type of functions of a substation used in between the generation station and load end are :-
1. Voltage improvement
2. Power factor improvement
3. Frequency improvement
4. AC to DC conversation
And many more.
Components of electrical Substation:-
There are various types of electrical substation components are used but here we are learnt in different ways i.e., A substation has basically two types of electrical components are :-
1. Main components
2. Protective components
Main components:-
The component which are heart of the substation like, in voltages improvement substation main components is a power transformer, in power factor improvement substation the main components are capacitor bank, etc.
The main components is also installed on the middle area of the whole substation. And also this is the most expensive part of the entire substation.
Protective components:-
The components which are installed around the main components are known as axillary components or protection components.
From the word, protective we will also understand that this is used to protect the main components or the whole substation.
Some examples of protective components are lighting arrester, isolator, capacitor bank, relay circuit, instruments transformer, etc.
A list of electrical components used in the electrical substation :-
- Power transformer
- Isolator
- Circuit breaker
- Relay circuit
- Lighting arrester
- Surge arrester
- Current transformer
- Potential transformer
- Wave trapper
- Battery bank
- Bus bar
- Rectifier
- Inverter
- Insulator
- Gantry
1. Power transformer:-
The transformer is a static electrical devices which is used transfer of electrical energy from primary side to secondary side through the help of magnetic field. It main function is to transfer power from one circuit to another circuit which is isolated from one another without changing frequency.
Core type transformer used as a power transformer. It's has a highest efficiency as compared to other electrical devices which is 90 - 95% on full load.
2. Isolator:-
Isolator is protective device which protects the substation by performing switching operation on faulty or maintenance condition.
Basically, it's a type of disconnector switch,. Which disconnect the circuit on the no load condition. It is quenching the arc by using lengthing of arc phenomenon.
Under 132kv, isolator used of a manual / hand operated...... But above 132kv, it is necessary to used motor operated for the protection of human life from the arc. Because, as voltage increase then the intensity of arc increases which harmful for human being to closer it.
3. Circuit breaker:-
It is the protective device which is used to separate the faulty part to the healthy part is known as circuit breaker.
It's also define as "the equipment / device which disconnect the unhealthy part to the healthy part without affecting the stability of the power system. It's take action by getting signal from the trip circuit.
A circuit breaker has mostly two part in the one is fixed end and another is moving end, and this is normal connect to each other in a regular manner. But as a fault occurred, which is senses by the trip circuit first then given signal to circuit breaker to trip the circuit.
4. Relay circuit:-
A relay is a sensing element of the substation which detect the fault in the substation or around the substation. As the relay senses the fault then it's give signal to the circuit breaker without given give signal it's not to be operated. Thus, relay circuit is very important for the protection of the substation.
There is many types of relay circuit used but here we are only talking about one which is 'over current relay' - in this types of relay current transformer is used to senses the current in the network it's is set as the current of the circuit is increases above limit from the second of CT trip the circuit.
Related terms-
5. Lighting arrester:-
Lighting arrester is a type of protective device which is used in starting and last of the entire substation. It's given protection from the surge i.e., lighting surge and switching surge.
As the power supply pass through lighting arrester then it's behave as a higher resistive element and as the surge is pass through the lighting arrester then it's acts as a low resistive element. And grounding all the surge and protected the substation.
It is contained zinc oxide in it, in the from of the bricks and outer frame be like an insulator (creeping surface).
6. Current transformer:-
An instrument transformer which is transformed higher current value to the lower Current value which is easily measured by an ammeter is known as current transformer.
It is connected series with the circuit where current has to be measured. A current transformer is an step up type of transformer in which voltage has been increases but the current has been reduced same time to easily measured its value by a small ammeter.
It does not mean at all that the instrument gives an incorrect rating. But for correct we need to multiple with factor which is mentioned in the current transformer which is used.
7. Potential transformer:-
It is also a instruments transformer which is the higher voltage level to the lower voltage level for easily measured by an voltmeter is known as potential transformer.
It is connected with parallel to the load for calculating potential in it. A potential transformer is a type of step down transformer which step down the voltage. And by multiplying transformation ratio to the measured values we get the true value.
8. Wave trapper:-
It is a device which super impose high frequencies signal to the power frequencies signal transfer between two or more then two substations.
From the receiving substation, wave trapper separated the higher frequency signal to the power signal, and capture the higher frequency ( message Signal) to the operator and power signal ( f =50hz) further flow without any obstacles.
9. Battery bank:-
A lithium ion cell are connected in series or group of series to formed battery bank in the substations which is used as a back up supply while fault occurred in the substations. The following points which determines the use of batteries in the substations are:-
1. To operate the relay circuit and all the control circuit
2. All the indicators which are used in the control room are operated on DC supply.
3. Tab changer of power transformer are operated on DC supply as well as AC supply.
10. Bus-bar:-
A bus bar is a node in which all the equipment which is electrical charge are connected through it. Aluminum hollow conductor used as a bus bar in the substations
A hollow conductor used as a bus bar in the substations to reduce the corona loss on the line. As compared to the solid conductor hollow conductor has higher radius thus it has lower electric fields on the surface of the conductor and finally reduce corona effect.
There are various types of bus bar connection used are:- Bus bar
- Single Bus bar arrangement
- Single bus bar arrangement with Sectionalizer
- Double bus bar arrangement with bypass
- Double bus bar arrangement with bypass and bus coupler.
11. Switchyard:-
The switchyard is the inter-connected of all the equipment which used in substation to perform the switching operation while it's necessary. In the switchyard, all devices has on same voltage level.
There is proper separation is maintained between the device to make proper isolation between them which is very necessary from the protection point of view.
12. Rectifier:-
A rectifier used in the substations for converting HVAC to HVDC from the transfer from one end to another with the lesser losses. This type of substation are also known as converting which the nature of supply.
13. Inverter:-
These equipment is used for converting HVDC to HVAC supply from the utilization of the electrical energy because mostly of the load are used Ac supply. The converting substation are used where there is long distance of the supply is required.
14. Insulator:-
A unit which separate the electrical charge part to the dead part is known as insulator. It's used in the substations for the holding the bus bar and the transmission line for the proper supply of the electrical energy.
An insulator has a high resistive element for the block of the supply to the ground and very less loss between from the suppler end to the receiving end.
15. Gantry:-
A gantry is basically a steel pole type support structures in the substation which is used to support the electrical conductor from the near by transmission tower.
Frequently Asked Questions - FAQs
How many transformers are in a substation?
Basically, there are three different types of transformer used in the substations are :-
- Main transformer - used for step up or step down the voltage level.
- Current transformer - used to calculate in the conductor.
- Voltage transformer - used to calculate the voltage level in the line to neutral.
Why is DC supply used in substations?
The dc supply used in the substations for charging the battery bank and provide dc supply to all the control and relay circuit.
What are the three types of substations?
There are various types of electrical substation are:-
- Transmission substation
- Distribution substation
- Indoor substation
- Outdoor substation
What is GIS substation?
GIS stand for "Gas insulated substation". In another we can say that GIS is an indoor type substation in which is fully insulated which sf6 gas which is best protection against the arc.