Spark model for 1100kV GIS disconnecting switch

In order to make the VFTO simulation more accurate, the spark characteristic of disconnecting switch and modeling is studied. The experimental circuit of the 1100kV GIS is simulated, and according to various computing resistance formulas of spark channels, the spark generated by disconnecting switch operation is modeled. The simulated voltage waveforms of the load side are compared with the measurement results. The simulated VFTO is obtained when different disconnecting switch spark models are adopted, with low-frequency oscillations of 200 kHz and 6 MHz, high-frequency of 36 MHz and 56 MHz, and the frequency range is basically consistent with the experimental results. The circuit oscillation frequency is mainly the same compared to different high-frequency decay rate with different spark models. The comparison shows that the simulated voltage waveforms of the load side match the experimental data better than others when Kushner model is adopted. However, the high-frequency attenuation rate of the simulated voltage at the load side is slower than that of the measuring voltage when Kushner model is used. Therefore, further developments in Kushner model are needed in order to reproduce with better accuracy the dynamic behavior of the disconnecting switch spark resistance.