Suppression of Dual Harmonic Components for Five-Phase Series-Winding PMSM

Compared to open-winding machine topology, series-winding topology retains the advantages of high DC-link voltage utilization and reduces the number of switching devices. However, in five-phase series-winding permanent magnet synchronous machines (FPSW-PMSMs), x-y subspace and zero-sequence harmonic components (dual harmonic components, DHC) exist simultaneously. It would cause additional harmonic currents and torque ripple. Moreover, both the inverter and the harmonic back electromotive force would generate such DHC. Thus, this paper proposes a new deadbeat-based DHC suppression control scheme for FPSW-PMSMs. Firstly, the concept of deadbeat control is employed to calculate the reference voltages in different subspaces, including the x-y subspace and the zero-sequence subspace. Subsequently, the FPSW-PMSM drive topology with different sequences of winding connection and the corresponding basic voltage vectors are studied for the higher voltage utilization. Based on the above voltage vector analysis, a five-degree-of-freedom space vector modulation strategy is designed to realize the independent modulation in α-β, x-y, and zero-sequence subspace. It promotes the synthetic voltage vectors to different subspaces to track the reference voltages in the corresponding subspaces. Further, since the current sensors are integrated with the half-bridge power modules of the inverter, the current sensors could only measure the leg currents of the inverter, but not the phase currents of the PMSM due to the series-winding topology. Thus, the phase current reconstruction method based on leg current is proposed for FPSW-PMSM drive. Finally, both comparative simulation and experimental results are given, which validate the proposed control scheme and recognize the necessity of DHC suppression.