异频信号注入法测量配电网电容电流的研究

Research on Measuring Capacitance Current of Distribution Network Based on Pilot Frequency Current Signal Injection

介绍异频电流信号注入法测量配电网的电容电流,通过在母线电压互感器二次侧的开口三角端注入两个幅值相同但频率不同的非工频电流信号,测量开口三角端的电压值以及相对电流信号的相位角,计算电容电流值。根据该测量原理,对现场试验中出现的问题做出进一步分析,并用实例证明了试验中,若未退出消弧线圈和电压互感器一次侧高阻消谐器则对试验结果影响很大。在一定程度上为安全准确测量配电网电容电流提供参考。

The pilot frequency current signal injection method is presented for measuring capacitance current in distribution network. By injecting the same magnitude of two current signals, but different of the frequency, into the open delta of e see- ondary side of bus voltage transformer, and measuring the voltage value of the open delta and the relative phase angle of the in- jected current signal, the value of capacitance current can be calculated. According to the principle of measurement, the prob- lems occurred in the on - site test are analyzed in detail and proved by an example that in the process of the test if it did not withdraw from the are suppression coil and the high - resistance harmonic eliminator in primary side of voltage transformer, it will have a great influence on the test results, which provides a reference for the safe and accurate measurement of capacitance current in distribution network.