Analysis and experimental research of a new type of permanent magnet linear synchronous motor

WU Hong-wei， YANG Jia-jun， CHEN Yuan-xiong
（School of Mechanical Science and Engineering， Huazhong University of Science and Technology，
Wuhan 430074， China）

Abstract：Aiming at the problem of large thrust fluctuation of permanent magnet linear synchronous motor，the reasons of thrust fluctuation were analyzed，the frequency components of thrust fluctuation were analyzed by Fourier series，a method of phase shift superposition was put forward. Based on the method，two movers were arranged by phase shift superposition，and odd number frequency components of the thrust fluctuation were eliminated，then a kind of U-shaped iron-cored permanent magnet linear synchronous motor was put forward innovatively，and its application on machine tool was discussed. The comparative experiments of phase shift superposition with one and two movers were done. The finite element simulation verifies that phase shift superposition can largely reduce the thrust fluctuation and eliminate the magnetic attractive force between the stator and mover. Comparative experiments indicate that the thrust fluctuation is reduced to 2% of the effective thrust force. The U-shaped iron-cored permanent magnet linear synchronous motor based on phase shift superposition can be used on heavy-load machine tool and  transportation.
Key words： permanent magnet linear synchronous motor； thrust ripple； magnetic resistance； phase shift superposition； finite element analysis