高压内熔丝全膜并联电容器耐爆试验的分析研究

Analysis of Bursting Test of the High Voltage Internal Fuse All-film Shunt Capacitors

对高压并联电容器的耐爆试验过程及机理进行了深入分析,结合内熔丝电容器试验中所表现出的一些特异现象,吸取油开关爆裂试验的研究成果,指出电容器内油中发生燃弧所产生的压力波是造成电容器恶性爆裂故障的直接原因,而能量注入的速率(dW/dt)决定着压力波的幅值。因此电容器爆裂的直接原因是能量上升的速率dW/dt而不是注入能量的多少。另外,文章还着重分析了内熔丝在爆裂试验过程中的动作特性。试验表明,一些内熔丝全膜电容器耐爆试验过程注入能量很多,但壳体完好无损,这不仅与全膜介质击穿点短接不易起弧,而且与内熔丝动作特性有关,最后探讨了改进电容器耐爆能力的方向和措施。

Bursting test process and mechanism of the high voltage all-film shunt capacitors are analyzed. It is pointed out in this paper, through particular behavior of the internal fuse capacitors with combination of achievement of the oil switch bursting research, that the direct reason of capacitor bursting failure is due to the pressure wave produced by the are in capacitor oil, and the amplitude of the bow wave of the pressure is determined by the energy injection rate dW/dt. Therefore,direct reason for the bursting of capacitor is not due to injected energy but energy rising rate dW/dt. The behavior of the internal fuse in capacitor bursting test is also especially analyzed. It is shown in the test that a great deal of energy is injected during the bursting test of some internal fuse all-film ca- pacitors,but the capacitor ease is still in good condition without any damage. This is not only related to the dielectric system construction, but also to the fuse＇ s action behavior. Finally, the measures of improving the ability of capacitor to resist the bursting are discussed.