Harmonics compensation with constant DC-capacitor voltage-control-based strategy of smart charger for electric vehicles in single-phase three-wire distribution feeders under distorted source voltage and load currents conditions

This paper discusses the harmonics compensation of the constant dc-capacitor voltage-control (CDCVC)-based strategy of smart charger (SC) for electric vehicles (EVs) in single-phase three-wire distribution feeders (SPTWDFs) under the distorted source voltage and load currents conditions. The basic principle of the CDCVC-based harmonics compensation strategy under the distorted source voltage and load currents conditions is discussed in detail. The instantaneous power flowing into the three-leg pulse-width modulated (PWM) rectifier, which acts the SC, shows that the CDCVC-based strategy achieves balanced and sinusoidal source currents with a unity power factor. A digital computer simulation is implemented to confirm the validity and high practicability of the CDCVC-based harmonics compensation strategy using PSIM software. Simulation results demonstrate that balanced and sinusoidal source currents with a unity power factor in SPTWDFs are obtained on the secondary side of the pole-mounted distribution transformer during both the battery-charging and battery-discharging operations in EVs, compensating the fundamental reactive, unbalanced active, and harmonic currents. Simulation results also demonstrate that the CDCVC-based strategy of the SC balances the source-side active power with the load-side active power.