Research on Two-Quadrant Operation Control Strategy for BLDCM Based on Two-Stage Power Topology

The paper investigates the operational challenges of brushless DC motor (BLDCM) in the first and second quadrants, proposing a novel two-stage power topology that enables BLDCM operation in both quadrants using a single control strategy. The front-stage four-switch buck-boost (FSBB) power converter manages bidirectional energy flow, while the rear-stage three-phase full-bridge inverter handles motor commutation. The proposed topology offers simplified control, facilitating seamless transitions between quadrant operations. Conditions for achieving zero-voltage-switching (ZVS) turn-on in all FSBB converter switches are derived, enhancing converter efficiency. As the three-phase bridge solely performs commutation, torque ripple during non-commutation periods is effectively reduced.