Research and Development of Novel Transient Waveform Recording Fault Indicators Used in Power Distribution Networks

Transient waveform recording fault indicators are widely used to find the faulted line section in distribution networks. Fault indicators are consisted of three acquisition units installed on three-phase lines, an aggregation unit, and a master station. In this paper, novel fault indicators integrating measurement and communication functions are studied and developed. The workflow of the acquisition unit includes collecting current data, determining whether to start recording or not, notifying the acquisition units of the other two phases to start recording, and determining whether it is a short-circuit fault. The workflow of the aggregation unit includes determining whether the fault is a single phase-to-ground (SPG) fault or not based on the recorded data, determining the fault phase, uploading the recording file to the master station. In the case of a short-circuit fault, the aggregation unit uploads the initial fault location result to the master station. The master station locates the SPG fault by using fault location algorithms based on the uploaded recorded waveform data. The acquisition units and aggregation units are designed and implemented based on the low-power STM32 chip and the fault indicators completed the installation and testing work in the field. Field experiments have proven that the developed fault indicators work reliably and can effectively collect three-phase transient currents in the distribution network.