Sinusoidal Control of BLDC Motors Based on a New Power Factor Corrected Trapezoidal Pulse Width Modulation Method

Permanent-magnet (PM) brushless DC (BLDC) motors have become very popular and have been widely used for low-power applications in the last decade. Recently, supplying these motors with sinusoidal currents have gained considerable attention in the literature because of improvements in the motor performance such as torque-speed characteristic and efficiency. In this paper, common pulse width modulation (PWM) methods for supplying a BLDC motor with sinusoidal currents are discussed in detail, and a new PWM method, called trapezoidal pulse width modulation (TPWM), is proposed. Also, a power factor correction (PFC) technique is proposed to be used in sinusoidal control methods which increases the mechanical power and motor speed. Simulation and experiments are provided in order to show the effectiveness of the TPWM method and the PFC technique. The results show that applying the TPWM method along with the PFC technique achieves a better BLDC motor control because the utilization of the input DC voltage and torque-speed characteristic are improved. Also, the efficiency at motor rated load is increased.

Keywords:

Hall sensors , permanent-magnet (PM) brushless dc (BLDC) motor driver , space vector pulse width modulation (SVPWM) , sinusoidal pulse width modulation (SPWM) , torque-speed characteristic