Measuring of very fast transient overvoltage and very fast transient current generated by disconnector operating

摘要

To investigate the very fast transient overvoltage (VFTO) and the very fast transient current(VFTC) generated by disconnector operating, we develop 220kV GIS experimental circuit, VFTO measuring system using hand-hole capacitive voltage divider as primary sensor, VFTC measuring system using Rowgowski coil as primary sensor. Test results indicate that the GIS experimental circuit can realize the synchronous measurement of two VFTO measuring systems and one VFTC measuring system. Typical waveforms of VFTO and VFTC during disconnector operating can be obtained. VFTO measuring system has a high cut-off frequency of 350MHz, and a low cut-off frequency of 48mHz. These parameters entirely meet the VFTO testing during disconnector operating. The system bandwidth of VFTC measuring system is 10MHz. The primary frequencies of both VFTO and VFTC are 0.4MHz and 10MHz. The duration of lower oscillation frequency 0.4MHz is 30us, the duration of higher oscillation frequency 10MHz is 500ns. The measuring system has high system reliability, high measuring accuracy, strong electromagnetic compatibility, low energy consumption, convenient operating performance, which meets the VFTO and VFTC measurement.