Synchronization of Solar PV Array-BES Microgrid to AC Grid for Buildings Application

This paper deals with the microgrid based on solar photovoltaic (PV) - battery energy storage (BES) and its synchronization with alternating current (AC) grid for residential and commercial buildings application. This system performs harmonics mitigation, reactive power compensation, unbalanced load mitigation, smooth changeover between standalone (SA) and grid connected (GC) modes of operation. The PV array is connected in a double-stage to avoid the under-utilization of solar energy. Smooth changeover between GC mode and SA mode is carried with the help of a solid transfer switch (STS). The voltage source converter (VSC) helps to enhance the power quality. It works in SA mode using voltage based control and uses current based control for GC mode. The bidirectional converter(BDC) administers the charging and draining of the battery. It also regulates the DC link voltage. Performance of the system is validated through satisfactory results of simulations in MATLAB/Simulink. The system behavior is observed in both steady-state and dynamic conditions.