Natural Variable Modeling and Performance of Interior Permanent Magnet Motor with Concentrated and Distributed Windings

ABSTRACT

Interior Permanent Magnet (IPM) motor is widely used for many industrial applications

and has relatively high torque ripple generated by reluctance torque. Since the

configuration of the stator has great influence on reluctance torque, different stator

configuration is necessary to improve the torque performance of IPM motor. Natural

variable modeling and performance comparison of Interior Permanent Magnet Motor

with Concentrated winding (CW), Short pitched and Full pitched distributed winding

(DW) is presented in this project report. Three phase Interior Permanent Magnet Motor

with identical rotor dimensions, air gap length, series turn number, stator outer radius,

and axial length was studied with different stator winding configuration. Basic

parameters and machine performance, such as inductances, copper losses, power density,

efficiency at high and low speed, torque ripple, rotor speed with load torque, phase

currents, electromagnetic torque, controllability and demagnetization tolerance are

compared. As a means of supplementing analysis of the IPM motor, winding function

theory (WFT) is used to analyze the motor. Winding function theory has enjoyed success

with induction, synchronous, and even switched reluctance machines in the past. It is

shown that this method is capable of analyzing IPM motor with different stator

configuration and the simulations were carried out by using Embedded MATLAB

function. It was observed that, the concentrated winding IPM motor has a lower copper

loss of 0.3 kw and 3.7 kw at low and high speed respectively and 133 Nm high peak

torque developed, pull out power of 58 kw, torque ripple of 96 Nm, average torque of

142 Nm, demagnetization tolerance of 60%, amplitude of the fundamental winding is

26.45 and efficiency of 89. the short pitched distributed winding IPM motor has a lower

copper loss of 0.35 kw and 3.6 kw at low and high speed respectively and 116 Nm high

peak torque developed, pull out power of 57 kw, torque ripple of 71 Nm, average torque

of 185 Nm, demagnetization tolerance of 78%, amplitude of the fundamental winding is

27.53 and efficiency of 87. As for full pitched distributed winding IPM motor has a lower

copper loss of 0.35 kw and 3.6 kw at low and high speed respectively and 116 Nm high

peak torque developed, pull out power of 56 kw, torque ripple of 71 Nm, average torque

of 185 Nm, demagnetization tolerance of 78%, amplitude of the fundamental winding is

29.3 and efficiency of 88.