Suppressing Dual Zero-sequence Current in Dual Three-phase Open-winding PMSM Using Multi-zero-vectors Hysteresis Control

In a dual three-phase open-winding permanent magnet synchronous motor (DTP-OW-PMSM) system sharing a common DC bus, dual zero-sequence current (ZSC) loops are inherent, leading to increased inverter capacity usage, losses, and degraded operational performance. To mitigate ZSC, the dual zero-sequence equivalent circuit of the DTP-OW-PMSM system is established, and zero-vector combinations with significant zero-sequence voltage amplitudes are employed. Since the two sets of ZSC loops are independent, four zero-vector combinations can be determined. A ZSC suppression strategy utilizing hysteresis controllers is proposed. Compared with the PI controller, hysteresis controllers offer wider bandwidth and simplify control parameter tuning. Additionally, 180-degree decoupling streamlines vector selection for multiphase open-winding topologies. Furthermore, the modulation range of the proposed strategy is investigated. Finally, experiment in a direct-drive motor is implemented, and experimental results confirming its effectiveness.