Optimized Overcurrent Relay Coordination in a Microgrid System

Abstract

Microgrids are a conglomeration of loads and distributed generators at a distribution level network. Since this network is no longer a single source fed network, the typical protection strategies may not be deployed. Reconfiguration is a topology changing feature that is visible in microgrid. This is also another factor that is to be considered while protecting the microgrid setup. This paper proposes a protection scheme that has normal and fault currents captured for all topologies of the microgrid. For each topology, the optimized time multiplier settings of overcurrent relays are computed using Dual Simplex Algorithm. This aids in clearing the fault as fast as possible from the network. A 21-bus microgrid system is considered and the optimized overcurrent relay coordination scheme is realized for the same.

Keywords: Overcurrent Relay, Microgrid