The open winding motor system is a dual-terminal power supply topology structure, which is formed by opening the midpoint of the phase winding and driving each terminal with a converter. It has many advantages, such as high utilization rate of DC voltage, flexible control mode, strong redundancy and fault tolerance. The converter at both ends of the topology can adopt two DC power supply modes: independent bus and common bus, and the circuit structure is different. In this paper, firstly, the mathematical models of PMLSM in ABC coordinate system under two kinds of power supply modes are derived, and the mechanism of force fluctuation caused by asymmetric impedance of primary winding and harmonic of secondary permanent magnet flux linkage is analyzed. Based on this, the main focus and control strategy of force fluctuation suppression under two kinds of power supply modes are further analyzed. Finally, the correctness of the analysis is proved by system simulation.

open winding， dual-terminal， models of PMLSM， force fluctuation