A simulation based comparative study of optimization techniques for relay coordination with Distributed generation

Penetration of Distributed generation (DG) in a distribution system changes the fault current and unidirectional nature of power flow. This leads to loss of coordination between various relays present in the system. This paper discusses formulation of the problem to determine optimal relay settings of an overcurrent relay with and without DG added to a system. A proper combination of primary and backup relay is selected to avoid mal operation of relays and unwanted outages. Different optimization techniques have been used for attaining optimum coordination of OC relays. In this paper a relative study of some of those techniques has been done. A three bus radial system is simulated in PSCAD/EMTDC platform and programming is done using MATLAB software.