Multi-objective reconfigurable three phase off-board charger for EV

In this paper, a three phase off-board charger is proposed that has a bi-directional flow of active power. The charger uses both solar photo voltaic (PV) array and grid energy to charge the electric vehicle (EV) battery. Moreover, the charger also feeds the solar PV array and battery energy into the grid. To achieve this, the charger has a provision to act as a standalone generator to generate the sinusoidal voltage of reference amplitude and frequency. In case of grid outage, unavailability of solar PV generation, the charger feeds household loads. It acts as an uninterruptible power supply (UPS) and has the capability to synchronize with the grid voltage on grid restoration and maintains the uninterruptible power supply to the load. While feeding the nonlinear loads an improved linear sinusoidal tracer (ILST) algorithm is used to estimate the fundamental current component of load current, so that the current drawn from the grid is always sinusoidal and at unity power factor (UPF). The controller is designed to extract the maximum power in all operating conditions. Moreover, the controller is designed such that it takes the decision of power flow among the different energy sources based on the demand. The charger is designed for a three phase 230V (rms) line, 50 Hz supply. The charger performance is analyzed in various dynamic conditions.