消除相间电容电流影响的故障分量综合阻抗计算方法

An Improved Method for Calculating Fault Component Integrated Impedance to Eliminate the Influence of Phase-to-phase Capacitance Current

分析了区内、区外故障时,线路相间电容对故障分量综合阻抗的影响,并提出了消除相间电容电流影响的故障分量综合阻抗计算方法。在各相的故障分量差动电流中减去该相流向其他两相线路的电容电流,计算结果仅取决于线路对地电容。使用EMTP数据对该方法进行了仿真,结果表明,采用新方法后,计算结果更稳定,整定时仅需考虑线路对地电容,整定原则更加明确,定值裕度大。

The influence of phase-to-phase capacitance on fault component integrated impedance during internal and external region fault is analyzed. A new method for calculating the fault component integrated impedance which eliminates the influence of phase-to-phase capacitance current is presented. By subtracting the capacitive currents flowing through to other two phase from each phase fault component differential current, the fault component integrated impedance is only determined by line-to- ground capacitance. EMTP simulation results show that the calculation result of the new method is much more steady, only the line-to-ground capacitance is needed to take into account for setting. The setting rule is much precise, and sensitivity of the protection principle is improved based on the fault comoonent integrated impedance.