Solar Isolated Bi-directional Electric Vehicle Charger with Power Quality Enhancement Features

In this work, the analysis of a PV based isolated-bidirectional electric vehicle charger (IBEVC) for house-hold application is presented for EV battery charging and with simultaneous power quality improvement. When sufficient PV power is available, the electrical power generated by PV is used to charge EV batteries, residential loads, and feed power to the utility grid in this IBEVC system. When PV power is insufficient, the grid supplies active power to household loads and the EV battery and IBEVC provides reactive power. For harmonic compensation by IBEVC, the fundamental load current is extracted utilising the Logarithmic hyperbolic cosine (LHC) based algorithm. For bidirectional power flow to the battery for charging and discharging, the Dual active bridge (DAB) converter is utilised to provide isolation between the battery and the supply. Extended phase shift (EPS) modulation is implemented to reduce current stress in inductor current and device currents, and improves the efficiency of the DAB. The various operating modes of the IBEVC for EV battery charging/discharging along with the capability of power quality improvement are discussed in detail.