Performance assessment of supercapacitor energy storage integration into a renewable DC microgrid

Resilient operation of DC microgrids is seriously endangered by the unpredictable and volatile renewable generation, arbitrary load variations and unplanned disconnections from the utility grid. These instabilities can cause DC bus voltage fluctuations and significant power quality issues. Therefore, employing a robust, quick-responsive energy storage system with reduced lifetime degradation under frequent cycling operation, to maintain the power equilibrium, is a prominent solution in such circumstances. This study investigates the integration of a PI controlled supercapacitor energy storage (SCES) system into an islanded solar-wind DC microgrid. The proposed system is examined under normal and extreme climatic activity and under abrupt loading events. Simulations conducted in PSIM software demonstrate the efficacy of SCES employment, in terms of overall system stability and power quality.