Breakdown Characteristics Of Gas Insulated Switchgears Fornon-standard Lightning Impulse Waveforms Underrnnon-uniform Electric Field

摘要

To improve insulation specification of a gas insulated switchgear (G1S), it is necessary to recognize the insulation characteristics of SF_6 gas under actual surge (called non-standard lightning impulse waveforms; hereinafter referred to as non-standard-LIWs) occurring in the field substation. The authors had observed the insulation characteristics of SF_6 gas gap under various types of non-standard lightning impulse waveforms and compared them with under standard lightning impulse waveform quantitatively. From the investigation of the experimental results, the evaluation method for real surges is shown and the method is applied to typical surges for various UHV and 500 kV systems. In the proceeding study, therefore, only for the quasi-uniform electric field (with a typical range of the field utilization factors in the bus of a GIS) was investigated. In this paper, the insulation characteristics of SF_6 gas gap for non-uniform electric field were observed experimentally and investigated about the evaluation method of converting non-standard lightning impulse waveforms equivalently to the standard lightning impulse waveform.