多断口真空开关的绝缘与击穿统计特性

从长间隙真空开关的击穿特性出发,理论推导得到了双断口及多断口真空开关的击穿电压最大可能增益倍数,并运用“击穿弱点”的概念和概率统计方法建立了双断口及多断口真空开关的静态击穿统计分布模型,认为无论是双断口真空开关还是n个断口串联起来,其击穿的统计概率都比单断口的击穿统计概率小。建立了三断口真空开关试验模型, 对单断口真空灭弧室模型和三断口真空开关模型进行了大量的冲击击穿特性试验。研究表明,三断口真空灭弧室比单断口真空灭弧室具有更低的击穿概率,试验数据与理论分布曲线基本吻合。

Dielectric Strength and Statistical Property of Single and Multiple-Break Vacuum Circuit Breakers

Based on the analysis on breakdown property of vacuum circuit-breakers (VCB) with long distance gaps, the maximum possible improvement factor K of breakdown voltage of VCBs with double breaks or multiple breaks in high voltage power system is theoretically deduced. Applying the concept of breakdown weak points and probabilistic method, the statistical distribution models of static breakdown for VCBs with double breaks or multiple breaks is established. The authors think that whether for VCB with double breaks or that with multiple breaks connected in series the statistical probability of breakdown is lower than that of single break. The experimental model with single break and that with triple breaks are built up respectively, and a lot of impulse breakdown tests for vacuum extinction chamber model with single break and VCB model with triple break are conducted. The research results show that the breakdown probability of vacuum extinction chamber with triple breaks is lower than that of vacuum extinction chamber model with single break, the testing data basically coincides with theoretical distribution curve.