Adaptive Relay Setting for Protection of Distribution System with Solar PV

Integration of solar photovoltaic (PV) in the distribution network causes bidirectional power flow which requires modification in Directional Overcurrent Relay (DOCR) setting to ensure proper coordination of relays. However, it is challenging to update relay setting with varying capacity of PV plants otherwise may lead to maloperation of relays. This paper proposes an adaptive protection scheme to overcome the challenges of the DOCR in distribution systems with PV. The method receives data about the capacity of PV plant through a communication channel to update the trip characteristics of the relays. Proposed method is tested for 34-bus distribution system and found to be accurate. Hardware-in-loop (HIL) validation of the proposed method is performed using Arduino uno microcontroller board as relay with OPAL-RT platform.