Simulation study on the influence factors of dynamic capacitance of SF6 circuit breaker during breaking

SF₆ circuit breakers are widely used in power system. Due to the accumulation of arc ablative effect, the arc contact state of SF₆ circuit breakers deteriorates continuously, which will lead to the decline of the insulation grade and breaking capacity of the break chamber. The dynamic capacitance simulation model of SF₆ circuit breaker was established, and the dynamic capacitance influencing factors were studied. Simulation study of the static arc contact length, static arc contact ablation angle, dynamic arc contact inner diameter and arc contact surface fluoride on the dynamic capacitance characteristics. The establishment of a comprehensive consideration of deterioration caused by various changes in the contact simulation model and test results for comparison, the results show that with the increase in the degree of comprehensive deterioration, the dynamic capacitance curve just split point travel down, just split point capacitance rise, completely split point capacitance is unchanged, the rule of change and the test results are consistent with the validity of the contact deterioration model.