Optimal placement of protective devices for improving reliability indices in Microgrid system

An increasing penetration of distributed generation (DG) in distribution systems has led to the concept of Microgrid. Reliability enhancement is one of benefits of Microgrid system because it can operate in both grid-connected mode and islanding mode. However, system protection is one of the important issues in Microgrid planning because operation mode and location of protective devices have effect on system reliability. This paper will present an algorithm to determine an optimal placement of protective devices in Microgrid system for improving reliability indices considering operation mode. The objective functions are to minimize three reliability indices that are system average interruption frequency index (SAIFI), system average interruption duration index (SAIDI) and energy not supplied (ENS). The proposed algorithms for solving the optimization problem and reliability evaluation are Particle Swarm Optimization (PSO) and Monte Carlo Simulation (MCS), respectively. Simulation results of implementing the proposed approach on modified feeder4 of RBTS bus 6 show the performance of this method.