Research on VFTO Simulation Analysis of 1000 kV GIS Test Circuit Considering Dynamic Arcing Model

In the research process of very fast transient overvoltage (VFTO), the accuracy of the switching arc model largely determines the calculation results of VFTO. How to more accurately simulate the arc striking and extinguishing process of the arc during the action of the disconnector is the key issue in the study of the arc model. In this article, the ATP-EMTP electromagnetic transient program was used to simulate arc damping with a series connection of a fixed-value resistance and a time-varying inductance, and the built-in MODELS module was used for programming to simulate the reignition and extinguishing process of the arc based on the gaseous dielectric theory and the energy balance theory. The model was applied to a 1000 kV gas insulated substation (GIS) test circuit. The relationship between the arc damping and arc voltage and current was analyzed, and the arc reignition law during opening and closing is studied. The arcing law obtained is compared with the experimental results of the existing literature, and the accuracy of the simulation model is verified. Simultaneously, the influence of the opening speed of the disconnector on VFTO was analyzed by simulation. The results show that when the opening speed is less than 0.7 m/s, the maximum value of VFTO in the test circuit increases with the increase in opening speed. After the VFTO amplitude reaches the maximum and continue to increase the opening speed, the VFTO amplitude decreases. This law is consistent with the experimental results of the existing literature, which proves that the arc model built in this article has a certain engineering application value.