Spatial Active Zero-State-Based SVM Strategy for Series-End Winding PMSM With Common-Mode Voltage and Zero-Sequence Current Suppression

Due to high dc-link voltage utilization and less required power devices, series-end winding machine drives have potential applications in permanent magnet synchronous machines (PMSMs). However, the zero-sequence current distortion increases the torque ripple and the overall power loss of the machine drive system. Besides, the common-mode voltage caused by the modulation strategy also impairs the lifespan and performance of both the converter and machine sides. Nonetheless, the combined suppression of zero-sequence current and common-mode voltage for series-end winding machine drives has not been reported until now. Thus, a spatial active zero-state-based space vector modulation (SVM) strategy is proposed in this article, where two spatial voltage vectors are selected to replace the zero-voltage vector. Moreover, a virtual voltage vector is established to cope with the high switching frequency in the proposed method, which makes the switching actions exactly the same as traditional 3-D SVM strategies and lower than the existing active zero-state-based SVM. The experimental results are carried out to verify the effectiveness of the proposed strategy, and it shows that comparable converter and machine common-mode voltages, better current distortion suppression effects, lower power loss of the converter, and higher machine efficiency can be realized compared with the existing active zero-state-based SVM strategy.