Undisturbed Operation of Symmetrical Dual‐Channel Electric‐Drive–Reutilized Onboard Chargers Incorporating Zero Charging Torque

ABSTRACT The dual‐channel electric‐drive–reutilized onboard charger (EDROC) originates from the design philosophy of the dual‐channel electric drive system. It features a modular design and high reliability, making it highly suitable for electric vehicles (EVs). However, multiphase motors are susceptible to open circuit faults, which can cause the system to malfunction. To address this issue, this paper investigates an undisturbed operation of the dual‐channel EDROC, which integrates a symmetrical six‐phase permanent magnet synchronous motor (SSPMSM) drive. First, the vector space decomposition (VSD) technology is employed to decouple the winding currents under prefault‐ and postfault conditions, demonstrating that a charging torque exists in the motor during a single‐phase open circuit fault. Then, a subspace current injection strategy is proposed by deducing the relationship between α ‐ β subspace currents and rotor angle, which achieve zero charging torque at almost all rotor angles. On this basis, rotor angle under the constraint of minimum copper is derived by constructing the objective function. Subsequently, an undisturbed operation controller is developed for prefault and postfault conditions. Finally, the feasibility and reliability of the proposed method are validated experimentally.