Two-Phase Interleaved DC Charging Method of Integrated Charger for Efficiency Enhancement

Lately, the battery voltage of electric vehicles (EVs) has risen, a twofold increase from the previously commercialized models. However, the adoption of high-voltage batteries has introduced a challenge for the use of lower-voltage fast dc chargers. To address this issue, integrated step-up charging topology that utilizes the motor drive system has been studied. In this paper, a two-phase interleaved integrated charging strategy is proposed. Only two phases of the motor are utilized to boost charge the battery while regulating the generated dc torque to zero. To ensure a standstill condition during charging, the torque produced by the zero-sequence components is also analyzed. The proposed strategy further reduces core losses by diminishing the current ripple in the windings, thereby improving energy efficiency. The feasibility of this work is theoretically assessed, and the experimental results demonstrate the effectiveness of the proposed strategy.