Analysis and Suppression of Thrust Ripple in a Permanent Magnet Linear Synchronous Motor—A Review

Nowadays, Permanent Magnet Synchronous Linear Motors (PMLSMs) are widely applied as direct drive mechanisms in the industrial manufacturing sector, which can fulfill the requirements for high precision and high production rates. However, PMLSMs are characterized by significant thrust ripple issues, including cogging force, ripple force, and end force, which severely deteriorate the operational accuracy. This paper provides a review of analysis and suppression of the thrust ripple characteristics in PMLSM, aiming to offer guidance on how to mitigate the thrust ripples, and hence, enhancing the operational accuracy of PMLSM system. Firstly, the structural features and operating principles of PMLSMs are analyzed to understand the causes of thrust ripples. Then, strategies for mitigating the PMLSM thrust ripples are elaborated upon, respectively, from two main perspectives: structural optimization and control strategies. Finally, a summary and outlook are presented.