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