Space voltage vector pulse width modulation method for dual three-phase permanent magnet synchronous motor

For the problem of large common-mode voltage (CMV) in the drive system of dual three-phase permanent magnet synchronous motor (DT-PMSM), a novel space vector pulse width modulation method (N-SVPWM) was proposed. Firstly, the causes of the fifth harmonic current and common mode voltage in the DT-PMSM drive system were analyzed. Secondly, three adjacent vectors were used to synthesize virtual voltage vectors to reduce the generation of fifth harmonic current. The virtual voltage vector and equivalent zero voltage vector were introduced to synthesize the reference voltage vector. The proposed method reduces the amplitude of the common-mode voltage to 1 / 6 of the DC bus voltage, effectively reducing the motor shaft current. At the same time, the proposed method also optimizes the action sequence of voltage vectors so that the switching devices of each phase change only twice in a switching cycle. The unfixed state (0 or 1) was designed at the boundary of each switching cycle, thus DSP and other digital implementation is easy. Effectiveness and feasibility of the proposed method are verified by comparison with the adjacent two-vector SVPWM (NTV-SVPWM) and the maximum four-vector SVPWM (MFV-SVPWM). © 2023 Editorial Department of Electric Machines and Control. All rights reserved.