Simulation Of Brushless DC Motor Research Articles

Modeling and Simulation of Brushless DC Motor with Nonideal Back EMF

The back electromotive force (EMF) waveform of brushless dc motor (BLDCM) is trapezoid. But it is not absolutely trapezoid because of motor manufacturing. In this paper, a method of modeling for BLDCM with nonideal back EMF is presented. Eighteen states during an electric angle cycle are obtained after the nonideal back EMF of BLDCM is analyzed. The S-Function of MATLAB is used to generate the nonideal back EMF according to rotor speed and position. The pulse width modulation (PWM) current control of BLDCM is adopted. Simulated results validate the method.

BLDC 모터의 열적 성능에 대한 설계 인자의 영향

A numerical simulation of brushless DC motor is performed to elucidate thermo-flow characteristics in winding and bearing with heat generation. Rotation of rotor and blades drives influx of ambient air into the rotor inlet. Recirculation zone exists in the tiny interfaces between windings. The flow separation causes poor cooling performance in bearing part and therefore the redesign of the bearing groove is required. The design parameters such as the inlet location, geometry and bearing groove threshold angle have been selected in the present simulation. As the inlet location moves inward in the radial direction, total incoming flow rate and heat transfer rate are increased. Total incoming flow rate is increased with increasing the inlet inner length. The effect of the bearing groove threshold angle on the thermal performance is less than that of other design parameters.