单星形接线电容器组击穿故障下桥差电流保护公式推导

Derivation of Bridge Differential Current Protection Formula under Breakdown Fault of Capacitor Bank with Single Star Connection

摘要:

在电容器内部元件如果发生击穿故障时，电容器组的电容会随之发生变化，将导致中性点电压发生偏移和不平衡电流的产生。首先，对电力系统中补偿电容器组的桥差保护计算公式进行推导，对电容器组单星形接线形式进行公式整理；然后，通过MATLAB建立Simulink仿真模型，对不同击穿率下的电容器组运行情况进行仿真分析，然后通过仿真数据对推导公式加以验证。

Abstract:

When the internal components of capacitor break down, the capacitance of capacitor bank will change accordingly, which will lead to the deviation of neutral point voltage and the generation of unbalanced current. Firstyl, the calculation formula of bridge differential protection of compensation capacitor bank in power system is deduced, and the single star connection form of capacitor bank is sorted out. And then, the Simulink simulation model is established by Matlab with examples, and the operation of capacitor banks under different breakdown rates is simulated and analyzed, and then the derived formula is verified by simulation data.