高压并联电容器的内部元件故障保护分析

Analysis of Protection Against Internal Element Fault in High Voltage Parallel Capacitors

通过对典型结线的电容器内部元件故障状况的计算分析,提出电容器保护的任务是限制事故范围,避免发生由电容器着火而扩大为变电所、电力系统事故。电容器内部元件故障保护应以不平衡保护为主,其动作定值按元件故障率a_1=35%～50%确定、时间定值t=0.1s;三相电容器组不允许缺台不平衡运行。

Through the calculation and analysis of internal element faults of capacilors in typical connection scheme,this paper points out that the purpose of capacitor protection is to limit the extention of fault and to avoid the fire hazard of capacitor spreading to an accident of the substation and system, Main protection of capacitor against internal element faults should be the unbalance protection with actuation setting value determined at an element fault rate α1=35% -50% and time setting t = 0.1s.Unbalanced operation due to deficiency of capacitor is not allowed for 3-phase capacitor bank.