A Presentation On Summer Training At Power Grid Corporation Of India Limited, Bahadurgarh

What is POWERGRID??? The Power Grid Corporation of India Limited (POWERGRID), is an Indian state-owned electric utilities company headquartered in Gurgaon, India. POWERGRID transmits about 50% of the total power generated in India on its transmission network. India’s largest Electric Power Transmission Utility.

400/220 KV Substation ,Bahadurgarh 400 KV Lines 220 KV Lines Key to abbreviation BH - Bhiwani BW - Bawana S1 - Sonepat Line 1 S2 - Sonepat Line 2 N1 - Nunamajra Line 1 N2 - Nunamajra Line 2

Different parts of Bahadurgarh substation Switchyard Control room Battery room Firefighting pump house D.G. set room AHU room ACDB/DCDB room

Switchyard 1.Interconnecting transformer 5.Isolator 2.Lightning arrestor 6.Circuit breaker 3.Capacitive voltage transformer 7.Current transformer 4.Wave trap 8.Earth switch

1.Interconnecting transformer The ICT is a step down transformer. It has three windings. Primary or High voltage (HV)-400 KV, secondary or intermediate voltage (IV)-220 KV, tertiary or low voltage (LV)-33KV.

2.Lightning arrestor It avoids the over voltages from entering the switchyard. Protection of the buses and equipment during Lightning surges. TYPES : Silicon Carbide (SiC) – Gap type Zinc Oxide (ZnO) - Gapless

3.Capacitive voltage transformer The CVT is used for metering purpose for monitoring the line voltages. The CVT is used for protecting the line against over voltages by connecting to relays which form the protection circuits.

4.Wave trap A wave trap is a device that allows only a particular frequency to pass through it that is it filters the signals coming onto it. It is installed in the phase which is used for PLCC.

5.Isolator An isolator is basically a switch that can be operated mechanically or electrically as well. The isolator cannot be used to shut down a line in loaded conditions as in an isolator arc is not quenched. This arc can damage the isolator or other equipment. Double Break Centre Break

6.Circuit breaker To breaks a circuit either manually or automatically under all conditions at no load, full load or short circuit. It can be used to discharge the line in loaded conditions also. The CB may be of different types: Air Blast Circuit Breakers SF6 Circuit Breakers Vacuum Circuit Breakers Oil Circuit Breakers

7.Current transformer Current transformer (CT) is an equipment that steps down or steps up the value of current as required. Functions of CT : Electrically isolates the instruments and relays from High Voltage side. Measures / monitors current. Used in Measuring power flow. Senses abnormalities in current for system protection.

Current transformer

8.Earth switch An Earth switch is used to provide ground to the Electrical circuit required for maintenance. It is mounted with the Isolator.

Control room Metering and control panels Protection/relay panels PLCC Different equipment in the control room are listed below: Metering and control panels Protection/relay panels PLCC

Battery room In the battery room, batteries are installed which provide DC supply for the substation operation. DC supply is required for the operation of relays in the control panel and for the operation of PLCC.

AHU room The control room is very large. The control room needs to be air conditioned so that the relays can operate normally. For cooling the control room an air conditioning plant has been installed in the substation on the roof of substation.

Firefighting pump house The firefighting pump house is connected with two water tanks. In the pump house four different pumps are present there which work in different conditions of water pressure. There are two jockey pumps, one Diesel engine set pump and one HVW pump. There is an air vessel that maintains the pressure in the pipes when the water flow is low.

Firefighting pump house