Single Phase Brushless DC Motor with PWM Control Strategy and Special Form of PM Rotor

This paper describes a mathematical model for electromagnetic simulation of a single phase brushless DC motor with special form rotor magnets, stator periphery and stator distributed winding.The rotor permanent magnets are mounted on the rotor in such a way as to enhance the flux distribution in the airgap so as to reduce the torque fluctuations and achieve the optimized torque. The obtained results are analyzed and decomposed in harmonic spectrum by means of Fast Fourier Transform (FFT) in order to determine the highest order harmonics and the best way to eliminate them. Analytically obtained motor characteristics are discussed for a wide range of parameters such as Pulse Width Modulation (PWM) control strategy,modulation index, induced voltage waveforms and control signal width and shape.