Theoretical Analysis and Experimental Verification of Switching Current Transient Process of High Voltage Switch-gear Circuit Breaker

Abstract

The internal overheating of the high-voltage switchgear is mainly caused by the internal transient current. The existing literature focuses on the decomposition of SF6 gas in the insulation medium after the internal overheating of the switch-gear, but the causes of the internal overheating fault are less introduced. In view of this, this paper attempts to analyze the typical analytical formula in the process of breaking the internal circuit breaker of high-voltage combined electrical apparatus from the theoretical angle. On this basis, the experimental platform is built to carry out the field simulation experiment of the circuit breaker fault opening and the closing process. In this process, the typical voltage and current waveform are obtained, which can be compared with simulation results of the theoretical formula mutual confirmation. Furthermore, the decomposition experiments of SF6 gas under the condition of transient current overheating are carried out on the simulation experimental platform, and basic decomposition products and their variation rules are determined under condition. The research results of this paper have good guiding value and practical engineering significance for understanding the transient over-voltage and current in high voltage switch-gear, and the local overheating phenomenon caused by it, and the overheating decomposition phenomenon of SF6 insulation gas.