Fault Location Method Based on the Zero-Crossing Characteristic of Current After ST Phase Control

The Sen transformer can achieve flexible interconnection of the distribution network, but the bidirectional flow of fault current after its connection makes the original fault location scheme of the distribution network no longer applicable. In response to this issue, a method for locating inter phase short circuit fault in flexible interconnected distribution network based on active control of Sen transformer is proposed. This method adjusts the equivalent transformation ratio of the Sen transformer through active phase modulation control, extracts the phase difference of the current waveform before and after the Sen transformer phase modulation control using waveform similarity, and construct the upstream and downstream phase change difference criterion, which can accurately locate the fault section of the distribution network. The proposed method does not require voltage information, is compatible with distributed feeder automation systems, has low communication requirements and does not require data synchronization, improving the accuracy of fault section localization in distribution network. The correctness and feasibility of the proposed method are verified based on the PSCAD/EMTDC simulation platform.