A Single Stage Single Phase Micro-Inverter with Inherent Active Power Decoupling Mechanism for PV-Grid System Based EV Charging Station

Two major challenges of single phase grid connected solar micro inverters, namely the Common Mode Ground Leakage Current (CMGLC) issue and the decoupling of Twice Grid Frequency (TGF) power ripple, have been addressed and solved in this paper. A novel topology of hybrid bipolar ‘boost-buck’ converter is proposed that can be mounted on each PV panel of level 1 Electric Vehicle (EV) charging station. The converter is capable of mitigating CMGLC due to its doubly grounded nature. A unique modulation strategy is adopted to shift the double grid frequency power ripple from the input PV terminal to an intermediate capacitor whose average voltage is controlled at a value higher than the sum of peak grid voltage and PV terminal voltage, thus reducing the size of all capacitors. Power-decoupled control of the converter is validated by PLECS simulation results.