Multi-Objective Optimization for Enhancing System Coordination Restoration by Placement of Fault Current Limiters on an Active Distribution System with System Reliability Considerations

Abstract

Nowadays, customer satisfaction relies on not only the power delivery, but also in the system reliability. It results a number of measures adopted by utility for reliability improvement. Moreover, distributed generators (DGs) are also enhanced to integrate to distribution system because DGs improve system reliability and capability. However, DGs can lead to mis-operation of protective devices and wider outage areas in power system due to increase in fault level. Moreover, system outage is the vital cause which decreases the system reliability. To mitigate escalation of fault level, fault current limiters (FCLs) are installed to limit incremental fault generated by DGs and improve system reliability. However, to enhance effectiveness of FCLs installation, non-dominated sorting particles swarm optimization (NSPSO) is adopted to find the optimal placement of FCLs. Moreover, novel binary particle swarm optimization and continuous particle swarm optimization are performed optimization simultaneously for selecting installed locations. Therefore, three objectives are considered in optimization process consist of to minimize total cost of fault current limiters installed, to minimize total different of margin operating time of main and backup relay pairs and to maximize system reliability. The optimal results are the set of various solutions conform with multi-objective placed in pareto optimal front, and the result show effectiveness of combined continuous-binary NSPSO. The optimization process is carried out on IEEE 33-bus and IEEE-69 bus radial system.