Dynamic simulation of brushless DC drive considering phase commutation and backemf waveform for electromechanical actuator

This paper proposes a model of brushless dc motor drive considering behaviour of the motor during commutation and waveform of backemf, for dynamic simulation of Electromechanical Actuator (EMA) under MATLAB/Simulink environment. Ideally trapezoidal backemf is considered in simulations for BLDC motor, which gives a constant torque. Practically, torque ripple exist, mainly due to emf waveform imperfections, current ripple and phase current commutation. Hence, an error can occur between real value and the simulation result. First a simple mathematical model of the BLDC drive is developed. The motor model is then simulated using MATLAB/Simulink, with sinusoidal and trapezoidal waveforms of backemf. A comparison study of results of both the cases is done. Finally the bldc motor model is integrated with the other models of the EMA and a dynamic simulation of the EMA is obtained.