Brushless DC Motor Driver for Electric Bike

Abstract

Brushless DC (BLDC) motors are preferred over brushed motors and in great demand for Industrial applications. MC33035/MC33039 based low cost BLDC motor control algorithm has been proposed. The design uses the Pulse Width Modulation (PWM) to control the rotational speed, and the Hall sensors examins the rotor position, and MC3035 received the position signal. In order to determine the exact pole commutation, MC33035 decoded the output of Hall sensors in the same time. Internal differential amplifier has been used to design the way of follower. PWM signal is obtained as the speed command signal directly compares with the saw-tooth wave. Closed loop speed control system is used to guarantee the velocity modulation precision request , and send the rotor position examination signal to MC33039, then transform after the frequency/voltage, which obtain a pulse signal for which motor speed is directly proportional to the frequency. After filtration, it is delivered to the negative terminal of MC33035 differential amplifier, then they compose a regulator, hence, to control the motor speed comes true in closed loop system. The brushless DC motor controller has been practically implemented on the bicycle