Fault-tolerant location of transient voltage disturbance source for DG integrated smart grid

In this paper, a new fault-tolerant approach based on improved particle swarm optimization (IPSO) is proposed to automatically locate the transient voltage disturbance source (TVDS) for smart grid with distributed generation (DG) integration. We first analyze the influence of the DG integration on the TVDS direction-judgments. Two new credibility indexes, the monitoring-credibility and the partial-credibility, are defined to measure the reliability of direction-judgment result at each power quality monitor (PQM) with consideration of multiple factors, including DG integration, disturbance intensity and fluctuation characteristic. By using these credibility indexes and a newly defined search space, a heuristic searching approach, called IPSO, is then proposed to obtain the optimal solution of the TVDS location. Simulation study is carried out on the IEEE 34 node test feeder, and the results demonstrate that the proposed approach has significantly improved fault-tolerant capability with satisfatory convergence speed.