Research on Very Fast Transient Voltage of 330kV GIS Disconnector Operation

With the increase of voltage level, the very fast transient overvoltage generated during the switching operation of GIS disconnector is an important factor threatening the safe and stable of secondary equipment. Based on the test data of 330 kV GIS disconnector switching operation, this paper extracts the characteristic of macropulse waveform and monopulse waveforms of the load side transformer and bushing, and makes a comprehensive statistical analysis of the transient waveform characteristic data. The results show that the duration of single breakdown of VFTO is generally more than ten microseconds, the time interval between breakdowns is ms level, the rise time is basically distributed in 0.1 ~ 9μs, and the VFTO dominant frequency is distributed in 1.9MHz, 20MHz and 6MHz respectively.