Torque Ripple Suppression For Open-end Winding Permanent-magnet Synchronous Machine Drives With Predictive Current Control

In order to suppress the torque ripple of an open-end winding permanent-magnet synchronous machine (OEW-PMSM), a q-axis current injection method is typically employed but the disturbances caused by the third flux linkage parameter mismatch can augment the torque ripple. To solve this problem, firstly, a zero-sequence current (ZSC) and zero-sequence back-EMF observer (ZCBO) were proposed based on an adaptive sliding mode control, which was able to simultaneously estimate ZSC and zero-sequence back-EMF under varying conditions. Based on this ZCBO, the estimated ZSC and zero-sequence back-EMF could compensate for the one-step control delay and suppress the aforementioned disturbances. Secondly, although central hexagon modulation is employed in the predictive current control (PCC) scheme, zero-sequence voltage (ZSV) still exists in the zero-sequence path due to the dead time of the inverter, affecting the predictive accuracy of the ZCBO. To accurately establish the ZCBO, the ZSV caused by the dead time of the inverter was considered in the ZCBO. Finally, a comparative study of two types of methods was presented, and simulations established by MATLAB software.