电容器组中熔断器非短路开断的电气特性

Abnormal-Fusing Electrical Characteristics of Fuse Used in Shunt Capacitor Bank

外熔断器是直接与电容器串联的保护器件,实际运行中,熔断器自身的非短路开断是电容器组附件中故障率最高的.目前广泛应用于电力系统的并联电容器组普遍采用分体框架式结构,由多台电容器联接成双星形后再接入电力系统.文中分析了开断过程的电气特性,推导了开断时的等效电气模型,得到了故障过程中电容器组的各支路电压及电流的相位规律,利用并联电容器组实时监测装置的故障记录数据验证了分析的正确性,并提出了降低熔断器引起电容器组故障率的建议.

Fuse is a protection device which directly connects with a capacitor in series. In practice, the abnormal fusing of fuse is of the highest fault ratio among the accessories of capacitor bank. Shunt capacitor bank is the compensation equipment generally used in power systems. It, commonly with framed structure, consists of several capacitors in a double-star structure linking to the power system. This paper analyzes the abnormal-fusing electrical characteristics of fuse, deduces an equivalent electrical model describing the fusing, and presents the phase rules of the voltage and the current of each branch in the capacitor bank with fault. The correctness of the investigation is then proved by the real-time fault data recorded by a monitoring equipment of shunt capacitor bank. Some suggestions for reducing the fault ratio of the capacitor bank are proposed in the end.