A Study of Motor Sensitivity to Parameters Variation in Exterior Permanent Magnet Synchronous Motor

Abstract

This paper presents the study of motor sensitivity to parameters variation on the dynamic behaviour of exterior permanent magnet synchronous motor with the aid of MATLAB m-file for simulation. This study is carried out due to factors that hinder the motor performance like limited speed range and high stator core loss. The motor differential models are indicated in reference frame of the rotor with rotor angular position, mechanical rotor speed, q- and d-axes stator currents as state variables. The motor parameters used in this research is a 3-phase, 2 KW, 50 Hz, 4 poles, 220 V. The results showed that increase in frequency leads to increase in motor synchronous speed (1500 rpm to 2250 rpm to 3000 rpm for 50 Hz, 75 Hz and 100 Hz respectively) due to its direct relation, and slightly increased electromagnetic torque and output power. The frequency variation helps in determining the motor speed range. The effect of increase in resistance of the stator winding shows that it reduces the magnitude of ripple of the output characteristics (torque, power and speed) but maintains the same steady state value, while the effect of increase in coefficient of viscous friction decreases the magnitude of ripple and increase the value of the steady state. Similarly, variation on the inertia moment of the motor has little or no effect on the motor output characteristics. Effect of load variation only affects the output power and air-gap torque of the motor as increase or decrease in load leads to increase or decrease in output power and air-gap torque respectively. The loading of the motor is not to exceed the 15 Nm otherwise, the motor will operate in reverse condition. The results gotten in this research as compared to other literatures gives a clear understanding and knowledge of the parameters required of a particular motor for improve operating performance with respect to the design requirement