How to Conduct the Lightning Impulse Withstand Test on 550kV GIS?

Cui Dong, Wang Jiansheng, Zhang Xiaoyong
HIMALAYAL - SHANGHAI - CHINA 

Abstract: With the rapid development of power grid in China, an increasing number of GIS are adopted in new substations. The lightning impulse test is recommended after the installation of GIS in order to check its insulation performance and reduce the risk of equipment failure. However, owing to the design and production, common lightning impulse generator with large capacitance load especially GIS cannot generate lightning impulse waveform, which meets the requirement. Therefore, based on lightning impulse withstand test of Three Gorges Right Bank 550kV GIS, models of lightning impulse generator and field equipment are established, and simulation calculation is done. According to the result, a method of installing the inductor in the impulse circuit is put forward to generate oscillating lightning impulse which meets the requirement of the test. This method is successfully applied in the test and results are good. Valuable experience has been accumulated for the lightning impulse test on GIS of 750kV, 1000kV substations in China.

AKey Words: Lightning impulse, GIS, wave front time, withstand voltage, field test,inductor