Composite Feedforward Compensation for Force Ripple in Permanent Magnet Linear Synchronous Motors

Abstract

This paper presents a method for compensating the force ripple in permanent magnet linear synchronous motors (PMLSMs) by adopting a composite feedforward compensation scheme. Firstly, the vector control system of PMLSMs is described, and various force disturbances influencing the electromagnetic thrust are analyzed. As a result, the mathematical model of the whole system considering the force ripple is established. Then, a novel composite feedforward compensation scheme is proposed, which consists of a recursive least squares (RLS) parameter identification component and two feedforward compensation loops corresponding to the reference position trajectory and the force ripple, respectively. Finally, the effectiveness and advantages of the proposed composite feedforward compensation are demonstrated by simulation. The main incentive of this paper is the combination with the composite feedforward compensation loop corresponding to the reference position trajectory to improve the compensation effect of force ripple in PMLSMs.