Computational analysis of a permanent magnet synchronous machine using numerical techniques

DONG JING

Publication

Computational analysis of a permanent magnet synchronous machine using numerical techniques

DONG JING

Abstract

This thesis deals with the computational analysis of a permanent magnet synchronous motor (PMSM) using finite element method (FEM). The objective is to couple the circuits directly with the field calculation in the dynamic analysis of PMSM. Parameters of two-axis model under different stator currents are determined from experimental measurement and FEM computation.Field - circuit coupled time stepping FEM is used to study the dynamics of PMSM. In the computation, 2D models combined with various circuits are used. The parameters of end effects due to stator windings and rotor end rings, obtained by analytical methods, are included in the circuits. The semiconductors components in the inverter circuit are simplified as resistors with different resistance values depending on their status. The mechanical movement of the motor governed by the kinetic equation is included also. The dynamics of the PMSM is computed step by step. The good match of the computational results with the experimental results suggests that the time stepping FEM with coupled circuits is a good tool for computing the dynamics of PMSM.In the determination of PMSM parameters, two novel methods using linear regression and Hopfield neural network have been proposed. Results obtained by these new methods are compared with those obtained by other researchers. The comparison showes improvements had been made by the new methods in the parameter determination. In addition, FEM is also applied to calculate the parameters. The effects of stator current on the parameters are taken into account in the calculation as well. The good agreement between the FEM results and the experimental results indicates that FEM is useful and applicable in predicting the PMSM parameters.