Field Measurement and Analysis on The Characteristics of Transient Enclosure Voltage and Transient Ground Potential Rise in UHV GIS Substation

Abstract

During the switching operation of GIS Substation, the Transient Enclosure Voltage (TEV)and the Transient Ground Potential Rise (TGPR) will occur, which will have a negative impact on the safety of substation. In this paper, TEV and TGPR are measured and analyzed in a 750kV substation at different locations of GIS, under three types of operation of disconnect switch and circuit breaker, include: single closing of disconnect switch, single closing of circuit breaker, three times opening and closing of circuit breaker. From the results, the maximum value of TEV and TGPR is 22.8 kV and 19.6kV, respectively, and the TGPR is higher than the TEV at many measuring points; Compared with the circuit breaker closing operation, the disconnect switch closing operation produces less electromagnetic oscillation energy, but it have longer macro-pulse duration and more breakdown times, which explained that the failure of secondary system caused by the operation of disconnect switch is more than caused by the operation of circuit breaker; Three times opening and closing operation of the circuit breaker produces stronger electromagnetic energy and more breakdown than single closing operation of the circuit breaker.