Adaptive distance relay scheme for a DG based network using RTDSTM

The power generated from Distributed Generations (DGs) such as wind and solar are eco-friendly and sustainable. Investigation on the impact of DGs on the power system network is presently a challenging task for the researchers. If the power generated from these energy sources are bulk and dispatchable then they are directly integrated into the transmission network. As transmission network is protected by distance relays, in-feed from DG will results in reach problems. This paper investigates on how the in-feed from DG source affects the operation of existing distance relays leading to over reach and under reach problems. The distance relay group settings are set in such a way that from the status of DG Breaker, the relay automatically switches to new settings which shows an adaptive approach, i.e., by communicating breaker status to the relay input contacts to make the relay adaptive based on the changes in the network topologies and to avoid maloperation of relay for effective protection, security of equipment and reliability of power transfer. This proposed adaptive scheme is implemented on a test transmission network simulated using Real Time Digital Simulator (RTDS) ^TM.