Speed Control of a Brushless DC Motor Using Rotary Encoder

Electric and hybrid electric vehicles need a drive system with high torque and simple controls. The BLDC (Brushless DC) motor is perfect for these uses and makes it easy to manage the speed. Even though it is quite complicated, it is possible to control the speed of BLDC motors by using accurate current-based regulation. A simple way to control speed is to use the output pulses from a rotary encoder with comparing them to a reference. This paper introduces a simple control system that uses rotary encoder pulses in conjunction with the dsPIC30F4012 controller. The error between the reference speed and the actual speed (measured in rotary encoder pulses) will be examined through hysteresis to provide a switching signal for the BLDC motor driving converter. Simulations and laboratory experiments were conducted to validate the analytical findings. The results of the simulation and testing indicate that the proposed controller operates efficiently.