介绍了中性点不接地系统常用的几种电容电流测试方法,包括直接接地法、异频信号法等。其中,直接接地法可以在投入或退出消弧线圈的情况下进行测量,异频信号法可以通过母线电压互感器开口三角、电容器中性点、接地变中性点等不同点注入进行测量。选取测试样本,采用以上测试方法开展系统电容电流实测。从测试误差、测试复杂度、测试工作量、测试风险、适用范围等5个方面对测试方法进行了综合分析评价,认为电容器中性点注入异频信号法最具工程推广应用价值。

The paper introduces some capacitive current testing methods such as direct grounding measurement method and pilot frequency current signal injection method. The direct grounding measurement method can be used when the arc suppression coil is present or absent. The pilot frequency method can be used for measurement by injection into the open delta of bus voltage transformer, neutral point of capacitor and the neutral point of grounding transformer. Test samples are selected to measure capacitance current of the system by the aforementioned methods. Through testing error, test complexity, test error, test risk and test scope of,the test methods are comprehensively analyzed and evaluated. It is considered that the method of pilot frequency injection into neutral point of capacitor is worth of engineering promotion and application.