Novel simple harmonics compensation method for smart charger with constant DC-capacitor voltage control for electric vehicles on single-phase three-wire distribution feeders

This paper proposes a novel and simple control method for the previously proposed smart charger for electric vehicles (EVs) on single-phase three-wire distribution feeders. The proposed method consists of only the constant dc-capacitor control, which is commonly used in active power line conditioners. No detection blocks of harmonic, reactive, and unbalanced-active currents are required. Thus, we propose the simplest algorithm to compensate harmonics, reactive, and unbalanced-active currents with the proposed smart charger on single-phase three-wire distribution feeders. The basic principle of compensation characteristics for harmonic currents is discussed in detail. A computer simulation is implemented to confirm the compensation characteristics for harmonic currents using PSIM software. Simulation results demonstrate that balanced and sinusoidal source currents with a unity power factor are obtained on the secondary side of the pole-mounted distribution transformer during both the battery charging and discharging operations in EVs, compensating harmonic, fundamental reactive, and unbalanced active currents.