Finite Element Analysis of Load Characterisitic and Parameters in Permanent Magnet Linear

Synchronous Motor with Structure Slots

Per Phase Per Pole Less Than 1

SHAO Bo¹  CAO Zhitong¹  XU Yuetong²  YU Peiqiong ³

(1. Institute of Applied Physics, Zhejiang University, Hangzhou 310027;
2. Institute of Advanced Manufacturing Engineering, Zhejiang University, Hangzhou 310027;
3. College of Information Engineering, Zhejiang University of Technology, Hangzhou 310032)

Abstract: By stability achievement of permanent magnet linear synchronous motor(PMLSM) with slots per phase per pole less than 1(q<1) fractional slot, thrust force density becomes the key point in analysis and design of the motor. To analyze the load characteristics, a finite element method(FEM) model of PMLSM is set up based on 2D electromagnetic field equations. Taking influence of end-leakage to PMLSM into account, open-boundary condition is used to improve the precision of analysis. With fixed three-phase winding current of fractional slot from space-time vectogram, relaxation factor method is used to adjust angle α. By iterating the normal rated thrust, load characteristic and parameters are obtained by instantaneous current method. Experimental prototype is used for parameter measurement. Comparing the FEM calculation with actual measurements, results show that FEM based model can confirm the load characteristic and obtain the parameters and power-angle characteristic of PMLSM. Direct-quadrature axis inductances give a good reference to the motion control of PMLSM.

Key words: Permanent magnet linear synchronous motor  Load characteristics  Direct-quadrature axis synchronous reactance

CLC No: TM359.4

国家自然科学基金(50475101)和浙江省自然科学基金(Y104193)资助项目. Received 20070327, received in revised form 20070921