Current Harmonic Suppression for Dual Three-Phase Permanent Magnet Synchronous Motor Drives

Due to motor asymmetry and system nonlinear factors, the dual three-phase permanent magnet synchronous motor (PMSM) drives produce a large number of current harmonics during operation. Based on the Vector Space Decoupling model, the six-phase currents of the dual three-phase PMSM can be decomposed into the alpha beta, the z(1)z(2) and the o(1)o(2) components. Speed and torque are controlled by controlling the alpha-beta current components. In addition, controlling the z(1)-z(2) current components is essential in suppressing current harmonics. In this paper, we propose two current harmonic suppression methods. Firstly, synchronous, anti-synchronous and bidirectional synchronous PI controllers are proposed to suppress current harmonics caused by different types of motor asymmetry. Secondly, a quasi-proportional resonance controller is proposed to suppress current harmonics caused by nonlinear factors of system. Simulation and experimental results demonstrate the effectiveness of the proposed methods.