Optimal Design of Expansion Chamber of High Voltage Self-Energy SF6 Circuit Breaker Based on Arc Simulation

With the increase of the rated voltage and current of the high-voltage self-energy SF
₆
circuit breaker, its breaking performance design is facing an astonishing challenge. The breaking performance of the circuit breaker is related to the generation, development and dissipation of high temperature airflow during the arc process. The gas flow causes the temperature of the expansion chamber is generally too high, resulting in the temperature of the arc cooling environment is too high at the current zero time. In some cases, it will lead to short-circuit current breaking failure. For the high-voltage self-energy SF6 circuit breaker, by simulating the entire arc breaking process, the expansion chamber gas pressure and temperature in the high current stage were obtained. At the same time, the arc shape and arc extinguishing environmental parameters in the current zero stage were obtained. Based on the results of arc simulation, the design of the expansion chamber structure was optimized, and simulation verification was performed again. Simulation results show that after the optimized design of the expansion chamber structure, the overall temperature of the arc-extinguishing environment at the current zero time decreases. The validity of this method is verified by comparison with the breaking test of the original circuit breaker prototype. The results show that the optimization design of the expansion chamber structure based on the arc simulation results can quickly and accurately determine the shape and size of the arc extinguishing chamber and significantly improve the breaking performance of the breaker.