What Are The Tests Performed On GIS Gas Insulated Stations?

What are the tests performed on GIS gas insulated stations?
Gas Insulated Substation?
- In the beginning, we have to know that there is a similarity between the tests that are performed on AIS stations and the tests that are performed on the GIS, but the difference is in the method of testing

- The tests of the station's equipment can be divided into: -
1- Knives (bars - ground)
Bus Dissconnector & Earth Switch
- Timing test is performed on all knives at different values of DC voltage in order to ensure that its motor works correctly if there is a decrease or increase in voltage
- Contact Resistance test to ensure the safety of the main contacts' connection
- 10 KV test and is performed on the Earth Switch only in order to ensure the integrity of the isolation and the absence of Leakage Current

2 - Circuit Breaker
- The Timing test is also performed on the key (O - C - CO - OC - OCO) in order to ensure the integrity of the mechanism
The (O-C) test is performed at different values of the DC voltage (80% - 100% - 120%).
- Contact Resistance test is performed to ensure the safety of the main contacts

3- Voltage and current transformers
- Test (CT & VT Characteristic)
- Test (CT & VT Loop) in order to ensure the safety of secondary connections and the absence of any open paths
- Primary test on current transformers, and here a current is injected with large values such as 800 amperes

4- Function Test
Here, the scheme is tested, the operating and separation and interlock are verified, and all modifications to the drawing are signed.

5 - Trip Test
And here the safety of the separation of all keys is ensured through the protective devices
- Before testing the High Voltage Test, the GIS must be charged with SF6 gas at the rated values, and its tests are conducted to ensure the quality of the gas and the absence of any moisture in it, and all Gauge test that it works properly with the alarm and the Block

6- High Voltage Tes Test
- This test is conducted after ensuring the safety of testing all the tasks mentioned above and with this test the Partial Discharge Test is also tested to ensure the safety of the GIS rooms and the absence of any irregular field within the GIS, which causes in the near future a collapse of the GIS