Analysis of Injected Current in End Compensation Coils on Detent Force and Thrust Ripple Reduction in Permanent Magnet Linear Synchronous Motors

This paper proposes a novel approach to mitigate detent force and thrust ripple in permanent magnet linear synchronous motors (PMLSMs) by integrating end compensation coils and employing injected current control. By combining a passive mechanism-through auxiliary teeth at both ends of the primary-and an active strategy-via harmonic current injection into dedicated end compensation coils-this method substantially reduces the no-load detent force and the thrust ripple under load. Finite element simulations demonstrate an 81 % decrease in no-load detent force and a 75 % reduction in rated thrust ripple. The proposed technique thus provides an on-line tunable strategy for enhancing thrust quality and positioning accuracy, making it highly suitable for high-precision and high-speed motion applications.