Integrating On-Load-Tap Changer in Service Restoration for a Distribution Network with Multiple PV Systems

In order to improve power system reliability, service restoration was operated to optimal radial topology when the line, transformer, and feeder outage occurred in the power system to restore maximum out-of-service loads with minimize switch operation and return the system to a normal state. In this paper, service restoration accomplished Sequential Opening Breach (SOB) by switching the status of several sectionalizing switches (SS) from closed to open. The problem includes four different objective functions: 1) maximizing the total load restored; 2) minimizing the number of switching operations; 3) minimizing power loss and 4) minimizing voltage deviation. Some tie-switches (TS) also needed to be changed from open to close to isolate the fault location due to the shorter service restoration during the broken portion made possible by the rising penetration of PV systems at the loads. To confirm the proposed method, the standard distribution system of IEEE 69 buses is tested with different load demands. The simulation results validated the effectiveness of the proposed method.