Harmonic Current Suppression for Open-Ending Winding PMSM Based on Voltage Injection

Since the advantages of multilevel output, voltage utilization rate and enhanced tolerant capacity, the open-end winding permanent magnet synchronous motor (OEW-PMSM) with common DC bus has received increasing research focus. Due to the distortion of air-gap magnetic field and nonlinear factors, different order harmonic currents are introduced to distort the current. Besides, due to the existence of the common DC bus, the 3rd order harmonic voltage would distort the fundamental currents more obviously. In the OEW-PMSM drive system, the disturbances caused by the harmonic currents would reduce the output performance. In this paper, by establishing harmonic mathematical model, a harmonic voltage injection method is proposed. The variables of the corresponding d-q coordinate system are decoupled. And the injection voltages are calculated by the reference currents, which are generated by simple closed-loop controllers. Simulation and experimental results are expressed to verify the proposed method.