Research of Multiple Arcing in 1000 kV GIS Disconnector Considering Fracture Capacitance

The accuracy of the arc model greatly affects the calculation results of very fast transient overvoltages (VFTO). Therefore, in order to accurately simulate the disconnector model, the fracture capacitance must be added to the disconnector model. In this paper, a single segmented arc model is combined with an arcing and extinction criterion. At the same time, the disconnector model with multiple arcing considering the fracture capacitance is constructed. Based on the above disconnector model theory, the ATP-EMTP electromagnetic transient program is adopted to realize the construction of the disconnector simulation model by using the built-in MODEL module of the software. The model is used for the 1000 kV test circuit. And influence of the fracture capacitance on the multiple VFTO waveforms on the power supply side and the load side is analyzed. The results show that the power supply side VFTO waveform do not differ much from the conventional waveforms after adding the fracture capacitance. And the high-frequency oscillation amplitude of the load side VFTO waveform differs more. This can provide reference value for the subsequent enhancement of disconnector safety.