Performance analysis of MPC-based Zero Sequence Current Controllers in an Open- Winding PMSM

For the open winding permanent magnet synchronous machine with common dc bus configuration, the suppression of zero sequence current is of paramount importance to reduce the total harmonic distortion of phase current and torque ripple. This article proposes a zero sequence current controller deploying model predictive control only along the zero axis and compares the performance with conventional 3-D model predictive current control scheme. In the proposed algorithm, several virtual voltage vectors are applied along the zero axis and the optimal voltage vector minimizing the cost function is selected as the reference zero sequence voltage. The reference zero sequence voltage is then synthesized by redistributing the duration time of zero vectors. It is shown experimentally that the proposed strategy performs better than the conventional 3-D model predictive current control in terms of total harmonic distortion of phase current and torque ripple.