配电网单相接地故障时的对地参数实时测量和选线方法

The ground parameters measured in the normal operation of a distribution network may lead to a poor arc suppression effect of the active current scheme after a single-phase grounding fault due to the change of the operation mode. In view of the above problems, this paper proposes a method of the real-time measurement for the ground parameters of the distribution network. After the single-phase grounding fault of the distribution network is detected, the active arc-suppression device is used to inject the characteristic frequency current signal. By measuring the neutral point voltage and the zero-sequence currents of the lines, the characteristic frequency component is extracted, and the system transition resistance and the total ground capacitance are calculated by the least squares fitting algorithm. In addition, the fault line selection can be realized by measuring the ground resistance of each of the lines. The simulation results on the PSCAD and the experimental results of the testing institution prove that the proposed scheme is able to accurately measure the ground parameters of the distribution network in real time under different fault conditions, and also achieve accurate fault line selection.