Detent Force Reduction in Permanent Magnet Linear Synchronous Motor Base on Magnetic Field Similarity Method

Abstract

Permanent-magnet linear synchronous motors (PMLSMs) have been widely used in various industries. However, the inherent detent force of these motors limits their application range, especially in high-precision motion and low-speed systems. In this study, magnetic field similarity (MFS) method and edgy teeth-shape optimization are proposed to reduce the detent force. First, an equivalent model of the PMLSM is established wherein the end effect is initially taken into consideration, and the parameters, such as reluctance, energy, and detent force, are calculated. Second, the principle of the MFS is introduced, and the main parameters that affect the detent force are obtained. The detent force is studied and analyzed using parametric analysis, and the shape of the edgy teeth is optimized by particle swarm optimization. The simulation verifies the correctness and applicability of the proposed method. Finally, a prototype is fabricated and the experimental results verify the validity of the mathematical model and simulation results.

Keywords

• Magnetic field similarity
• equivalent magnetic circuit
• finite element analysis
• tubular permanent magnet linear generator
• particle swarm optimization