Harmonic distortion mitigation for electric vehicle recharging scheme

Three harmonic mitigation techniques are presented to reduce the harmonic emission of a diode bridge rectifier based battery charger used to recharge the main propulsion batteries of a large scale electric vehicle. The hybrid electrical vehicle (HEV) studied here, uses a battery charger that produces current harmonics in excess to cause the control circuitry of the battery chargers to malfunction. This limits the number of chargers that can operate simultaneously. Extensive research is conducted to properly characterize the battery charger in order to design appropriate solutions for harmonic mitigation. The solutions include: better utilization of the internal harmonic mitigation inherent to the battery chargers, increasing the effective pulse number of the diode bridge and filtering the harmonics off the system. Simulations completed for each solution show that each of the solutions will mitigate the harmonics, to some extent, with two solutions allowing all twelve chargers to operate simultaneously. Overall the mitigation solutions provide a satisfactory operating environment on the power system.