SIMUALITON OF THE ARC DYNAMIC BEHAVIOR IN A 252KV PUFFER TYPE SF6 HIGH VOLTAGE CIRCUIT BREAKER

摘要

The arc dynamic behavior is of critical importance to the design of high voltage circuit breaker. Based on the 2-D MHD arc model, computer simulations of an alternating current arc (effective value 31.5kA) have been carried out in a 252kV puffer type SF6 circuit breaker chamber. The user-defined real gas model is used for imputing the gas properties of SF6. Timevarying characteristics of the arc temperature and gas pressure are analysed. Comparisons of the arc temperature distribution with that of the gas density, velocity and shock are carried out. The results show that the thermal gas flow field can be calculated reasonably. The arc evolution and hot gas backflow can be described clearly. The phenomena of nozzle blocking, shock wave and supersonic flow are presented. The simulated arc voltage is agreement with that of the short circuit interruption tests.