Selective Coordination Study in a Renewable Energy-Based Microgrid

The wide integration of renewable energy, such as photovoltaic and wind farms, into microgrids poses severe protection challenges due to the uncertain variations in solar irradiance and wind speed. The unpredictable behavior of renewable energy sources necessitates a more adaptable and optimized regulation of the protection devices such as over-current relays. Therefore, a protected 9-bus microgrid power system is modeled in ETAP based on IEEE standards in the presence of different renewable energy sources. Different power system analysis such as load flow, short circuit, relay coordination are studied in normal and contingency operation of the modeled microgrid. With the aim of improving the robustness of the protection system against weather intermittency, an algorithm is proposed to optimize the coordination between the relays in presence of different renewable energy sources. The performance of the proposed protection scheme has been evaluated for different case scenarios.