Open-winding Brushless DC Motor Phase-loss Operation Conduction Control Method

Three-phase brushless DC motors (BLDCMs) are widely utilized in the field of electric drives. Traditional BLDCMs typically adopt a star-connected configuration, where the presence of a neutral point among the windings results in lower reliability and significant commutation torque ripples. To address these issues, this paper proposes an open-winding BLDCM system, conducting a comparative analysis of various conduction modes to identify the optimal mode under normal operating conditions. Furthermore, it considers winding phase-loss fault scenarios, introducing a conduction mode better suited for phase-loss operation, effectively reducing torque ripples caused by winding open-circuit faults. The effectiveness of the proposed method is validated through simulations.