高压电容器单元用内熔丝性能

Internal Fuse Performance of High Voltage Capacitor Unit

内熔丝是高压电容器极间短路故障的重要保护措施,但是关于内熔丝分析计算目前还没有成熟的方法,内熔丝尺寸主要靠经验进行设计。为了得到电容器内熔丝的设计原则,开展了电容器元件击穿时的等值电路以及二阶电路理论分析,以特高压工程用BAM6.56-556-1W型电容器单元为例进行了计算、软件仿真和验证试验,得出了电容器元件击穿时流过击穿元件支路的暂态电流表达式和注入与击穿元件串联内熔丝能量的计算方法。利用该计算式得到的结果与EMTP-ATP软件仿真及试验结果一致,该成果解决了高压电容器单元用内熔丝能量计算和参数选择问题,研究成果可供内熔丝电容器设计参考。

Internal fuse is an important protective device against inter-electrode short-circuit of high voltage capacitor. However, no reliable method can be used in internal fuse analysis and selection. Currently, the parameters of the internal fuse are determined according to field experience. To solve the parameters selection problem of capacitor internal fuse, according to equivalent electrical circuits of a broken-down capacitor element and the second order circuit theory, the transient current flowed through broken-down device and the energy injected into internal fuse series connected with the capacitor are derived and given when the capacitor unit is broken-down. Taking BAM6.56-556-1W capacitor for UHV project as example, we carried out theoretical calculation, simulation and verification test, and the calculation, simulation and experimental results are consistent. The results can solve the internal fuse parameters selection problem of high voltage capacitor which can be taken as a reference to capacitor internal fuse design.