A novel relay used for fault detection and isolation in distribution networks containing of several DGs

Presence of Distributed generators (DGs) in the Distribution network using overcurrent relays for protect the Distribution network is a challenging task because of the changes in fault current levels and reverse power flow. Especially, in the presence of current limited converter interfaced DGs, using overcurrent relays are may fail to detect and isolate the faulty section while it is grid connected or islanded mode of operation. In this paper a novel Inverse type relay is presented here to protect a distribution network, which may have several DG connections. The characteristic of this new relay is designed based on the measured admittance value of the protected line. ITA relay is capable of detecting faults under changing fault current levels. The novel relay performance is valuated using PSCAD simulation.