A Combined Motor-Inverter Charger for EVs Based on Segmented Three-Phase Six-Winding Motor and Single-Phase Grid With Fault-Tolerance Capability

Abstract

This article proposes an integrated battery charger for electric vehicles (EVs) that combines a dual three-phase bi-directional converter (D3BC) and a segmented three-phase six-winding permanent magnet synchronous motor (S6-PMSM) into a single-phase charging system with high fault-tolerance capability. The charging circuit is created by connecting directly the single-phase grid to the motor winding terminals without modifying the motor. In this setup, the S6-PMSM functions as a single-phase ac inductance filter (a combination of self-inductance and mutual inductance), while the D3BC acts as a dual parallel single-phase rectifier (DP1R). In this proposed system, no additional devices (such as switches) are needed for the hardware reconfiguration that makes the system robust. Due to the magnetic interaction between rotor poles and stator slots, this context highlights the presence of cogging torque in PMSM during charging and vehicle-to-grid (V2G) operation. By parking the EVs with the rotor position at ${\pm }k\pi /\text {LCM}(N_{\text {poles}},N_{\text {slots}})$ , where $k = 0, 1, 2, 3, \ldots $ , a zero cogging torque is achieved. In charging/V2G modes, the proposed system operates with zero electromagnetic torque production, unity power factor (UPF), less than 5% total harmonic distortion (THD), and over 90% peak efficiency. A detailed theoretical analysis of S6-PMSM behavior in charging/V2G modes and its finite element analysis (FEA) is presented. The control algorithm with fault-tolerant control for the proposed integrated battery charger is provided. The experimental results are included to validate the theoretical analysis and simulations.