Adaptive Logic for Distance Protection of Feeder Connecting Renewable Energy

Extensive Converter-Interfaced Renewable Energy Power Plants (CIREPP) are of focused on integration with the grid. Fault Ride-Through (FRT) scheme followed by grid code is the capability of generation plant to stay connected in voltage dip even fault duration for some period to prevent the unwanted detach of Renewable Energy Plant (REP) from the power system. This scheme causes the phase angle difference between source end current and load end current. And modulates the voltage and current in fault duration, which can cause the calculated impedance with local data available at the relay is out of the trip boundary of the Distance Relay, which leads malfunction of the relay. The proposed scheme calculates the angle, which is a function of fault current with the help of realfault impedance of the REP and calculates the impedance from fault inception point to relay location point. The challenges brought by the FRT scheme studied and the proposed method verified on the IEEE-39 bus system integrated with a typical Solar power plant in PSCAD/EMTDC.