実規模配電系統での事故点標定のための電柱径間長に対応できる分解能を持つTDR測定

抄録

The authors propose a new and more efficient method to search for fault points by injected short pulse with high frequency into distribution line. This method, which is called as TDR measurement, enables to find the fault point easily by measuring propagation time of the pulse reflected due to impedance change at the fault point. In this paper, the proposed method is experimented in real-scale distribution system with about 700m distance which is isolated by DAS (Distribution Automation System) as outage area. The measurement result shows that an injected pulse with corresponding to utility pole span resolution is able to propagate through about 700m distance, and each reflected wave by several brunches and terminals is observed clearly in the real-scale distribution system. And the measurement result corresponds with the simulation result of the test equivalent circuit model. Moreover, the authors measured reflected waves from a fault point (short circuit, broken wire, or grounding) in test circuit. As the results, reflected waves from every fault point were confirmed by simulation, and they depend on the fault type. We calculated the fault location from the pulse velocity and the propagation time of the reflected wave, and the result nearly corresponded to the actual setting. In addition, the measured wave corresponds to the simulation result using equivalent circuit model of each fault point.