Suppressing the Thrust Ripple of the Consequent-Pole Permanent Magnet Linear Synchronous Motor by Two-Step Design

This paper investigates the thrust ripple of a consequent-pole permanent magnet linear synchronous motor (CP-PMLSM). The components of the thrust ripple are analyzed through the comparison of the thrust waves' constituent frequencies. A two-step design process is then proposed in order to reduce the different components of the thrust ripple. The first step consists of implementing a modular regulating structure and rewinding the coils in the resulting two sectional motors, through which the thrust ripples of the modular CP-PMLSM originating from the armature current and voltage harmonics are suppressed. In the second step, the geometrical parameters defining the magnetic regulating structure and the end-teeth are comprehensively optimized to reduce the detent force. By using the aforesaid procedure, it is shown that the CP-PMLSM can achieve small values of thrust ripple for different loadings.