Dual-Inverter-Integrated Three-Phase EV Charger Based on Split-Phase Machine
Caniggia Viana, Mehanathan Pathmanathan, Peter W. Lehn
Abstract
Significant effort has been dedicated to developing integrated onboard charging circuits for electric vehicles, aiming to improve cost, range anxiety, and charging convenience. The dual-inverter drivetrain topology has attracted particular attention as a platform for developing such solutions, being previously leveraged for the implementation of dc and single-phase ac onboard charging. This work proposes an integrated three-phase onboard charger based on the dual-inverter drivetrain. The proposed converter is implemented with minimal change to the dual inverter and no additional power electronics by introducing a split-phase electric machine. A mathematical model is developed, decomposing the system into four decoupled subsystems, individually responsible for charging, driving, grid common-mode current, and zero-sequence current generation, respectively. In light of this model, a novel space-vector pulsewidth modulation technique is introduced to ensure charging current control while generating no flux-producing, nor zero-sequence currents, and having superior common-mode performance. Simulation-based and experimental verification is conducted on a 7.2-kW scaled-down prototype to prove the charging concept, as well as the common-mode current elimination.