A Protection Scheme of Active Distribution Network Considering the Sequential Coordination of Grid-Connected Distributed Generation and Reclosing

Based on the analysis of the fault characteristics of the inverter interfaced distributed generation under PQ control and the influence of the distributed generation access on the traditional protection technology, an active distribution network protection scheme considering the capability of regional measurement is proposed. The protection scheme based on the direction of zone current is proposed for the region with enough capability of measurement. The distribution network is divided into zones, and the fault zone is judged by collecting the fault component of current at breakers. As for the region with poor capability of measurement, an reclosing scheme coordinated with DG re-grid timing is proposed. The proposed scheme effectively solves the influence of distributed generation access on traditional protection and reclosing of distribution network. The simulation results of the examples in PSCAD/EMTDC prove the effectiveness of the proposed scheme.