Abstract

The paper proposes a model of brushless DC motor considering behavior of the motor during commutation. The torque characteristic of BLDC motor presents a very important factor in design of the BLDC motor drive system, so it is necessary to predict the precise value of torque, which is determined by the waveforms of back-EMF.

After development of simple mathematical model of the BLDC motor with sinusoidal and trapezoidal waveforms of back-EMF the motor is simulated in the MATLAB/Simulink environment. Based on analysis of the time responses a comparison study of results of both BLDC motor types is presented in Graphical User Interface of MATLAB environment.