串联电容器极间介质设计场强选择

Selection of Electric Field for the Interpolar Medium of Series Capacitors

分析了串联电容器在各种工况下可能出现的过电压水平,并以此确定了串联电容补偿装置过电压保护器的保护水平电压Upl。以高压全膜并联电容器的极间介质设计场强为基准,得到了串联电容器在线路不同事故负荷电流和保护水平Upl时的宜用介质工作场强。建议带有串联电容补偿装置的线路按(N-1)方式运行时,其事故负荷电流不要超过1.4pu,以免串联电容器极间介质工作场强过低,导致串补装置设计成本过高。

This paper analyzes the overvohage level of series capacitor which possibly occurs at various conditions, and based on this, determines the protection level Upl of overvohage protector in the series capacitor compensation device. Taking the design electric field of interpolar medium of high voltage pp film shunt capacitors as criteria, obtains the suitable dielectric working electric field of the series capacitor at different load current and protection level of transmission line fault. It is suggested that when the line with the series capacitor compensation device operates in the duty of （N - 1 ）, the fault load current shall not exceed 1.4pu, so as to avoid high design cost of the series compensation device due to extremely low interpolar medium working electric field of the capacitor.