Improved Space Vector Modulation Strategy for Dual-Channel PMSM Based on Saddle-Shaped Modulation

The dual-channel permanent magnet synchronous motor (PMSM) processes advantages of high torque density, strong fault tolerance and high-power level. Nonetheless, the control quality is seriously restricted owing to the current harmonics and computation complexity, deriving from inevitably unbalanced power supplies and multi-dimension of voltage vectors. To this end, an improved space vector modulation (SVM) strategy is proposed in this paper. At first, to adapt the dual-power supplied system, the ratio of dc-links is included in the synthesized results, and subsequently the synthesized voltage vectors can be constructed with elaborate magnitudes and angles. Thereafter, the modified selection criterion is introduced from the aspect of suppressing current harmonics without additional calculation burden. Meanwhile, the undistorted saddle-shaped modulation waveforms are available to deal with the unbalanced supplies condition. In this sense, the harmonics and torque fluctuation are further optimized. Finally, experimental results prove that the improved SVM has a superior steady-state performance, equipping with quite low current harmonic distortion and intact saddle-shaped modulation waveforms.