短路电流对自能膨胀式高压SF_6断路器电弧开断过程中阀运动特性的影响

Influence of Short-circuit Current on Motion Characteristics of Valves During Breaking Process of High-voltage Auto-expansion SF_6 Circuit Breaker

单向阀的运动特性对自能膨胀式高压SF6断路器的仿真计算结果准确度具有直接影响。为此,提出了一种耦合了阀片运动的自能膨胀式高压SF6断路器磁流体动力学模型,对2种典型开断条件下(短路电流有效值为36k A和40 k A,燃弧时间15.3 ms)的燃弧情况进行了研究;对比分析了不同电流下灭弧室内的温度分布、气压分布、喷口烧蚀质量以及单向阀的运动特性。结果表明,40 k A条件下灭弧室内的整体温度和气压高于36 k A条件下;40 k A条件下的单向阀比36 k A条件下的单向阀提前0.8 ms动作,喷口烧蚀质量增加了0.35 g。

The motion characteristics of non-return valve has a direct influence on the accuracy of simulation result of high-voltage auto-expansion SF6 circuit breaker. To this end, we built a magnetohydrodynamic simulation model coupled with action of valves for high-voltage auto-expansion SF6 circuit breakers. Then we researched the arcing characteristics under two typical breaking conditions with short-circuit current of 36 kA and 40 kA and arcing time of 15.3 ms. The tem- perature and pressure distribution, the ablation mass of nozzle and the motion characteristics of non-return valve were analyzed. The results show that, compared with the case of 36 kA, the temperature and pressure in 40 kA case all increase the non-return valve acts earlier by 0.8 ms, and the ablation mass increases by 0.35 g.