A simulation-based investigation on the Performance of BLDC motor used in Electric Vehicles for varied magnetic materials

Abstract

Permanent magnet motors are widely used in Electric vehicles. Among the different permanent magnet motors, BLDC motors are preferred more. They are also used in industries for blowers, chimneys, and air conditioners because it provides high efficiency. In addition to these, BLDC motors are compact and have low noise compared to the other induction motors. The main disadvantage of the motor is the cogging torque, causing unwanted effects to the motor such as jerkiness, vibrations, and noises. Interaction of the permanent magnet present in the rotor with that of the stator slots leads to this undesirable effect of jerkiness. Reduction of cogging torque may be obtained by choosing either fractional slots per pole, and / or optimizing magnet pole arc or width, skewing stator stacks or magnets. The prime goal of this simulation work is to design a BLDC motor using fractional slots per pole configuration along with different magnet materials and grades. Rare earth materials with different grades are used for this simulation. These magnets offer high efficiency, but the disadvantage is that these magnets are expensive. This work elaborates the investigation of back emf, speed-torque characteristics, cogging torque, efficiency based on the material selection. MotorSolve has been chosen here for simulation of 24V, 3 phase, 4 poles, 27 slots BLDC motor.