Magnetic Field Analysis and Flux Barrier Design for Modular Permanent Magnet Linear Synchronous Motor

Modularization design has been widely used to reduce the detent force of permanent magnet linear synchronous motor (PMLSM). For modular PMLSM, ideally, unit motors are independent of each other and the detent force of the whole motor is the sum of that of unit motors, thus the whole motor detent force can be suppressed by adjusting the phase difference among the unit motor detent forces. But in fact, there is coupling effect between adjacent unit motors, which has adverse effect on the detent force suppression. The influence of the coupling effect is often neglected in current research. Hence, this paper carries out the research on the coupling effect for modular PMLSM: the influence of the coupling effect on the air magnetic field is clarified through magnetic field calculation; the coupling force is isolated by finite element analysis (FEA), and then the effects of key parameters are discussed; the detent force model considering the coupling effect is established, and an optimal design method adjusting the flux barrier length is presented to suppress the detent force.