Dynamic simulation of PM disc motor using MATLAB/Simulink coupled with finite element method

This paper describes the development of a basic permanent magnet disc motor (PMDM) simulation model for MATLAB/SIMULINK transient analysis. The PMDM model consists of SIMULINK blocks that can be easily implemented in a real-time test environment in order to investigate all different transient regimes of the motor. The simulation drive model is consisted of a PMDM model and a pulse width modulated (PWM) inverter model. The motor, modelled for this simulation is a prototype brushless three phase synchronous permanent magnet disc motor fed by a PWM inverter connected to a rechargeable battery supply or a fuel cell. Soft magnetic composite material is inserted as stator slots closure in the open slots, in order to reduce the torque pulsation because of the stator slot openings. This is very important due to the fact that this type of motor is designed for a direct wheel drive in electric vehicles (EV). Since this motor is in a development stage, beside its steady state characteristics it is essential to determine its transient regime performance and characteristics. For that purpose, a proper modelling of the motor and the whole drive is necessary. Some of the permanent magnet disc motor parameters necessary for the MATLAB/SIMULINK model are determined experimentally (R_s, L_d and L_q) and some are determined by using quasi-3D FEM calculation data (lambda_m). In order to be able to calculate the permanent magnets magnetic flux (lambda_m), an original modelling of the motor is performed, in which the motor is divided into five linear segments. For the analysis of the SIMULINK modelled PMDM drive, a start up regime simulation of the motor at no load and rated load is performed and the simulation results are presented.