Speed Control of a Brushless DC Motor Using Hall Sensor

Speed control using a Brushless DC (BLDC) motor typically involves adjusting the amplitude and frequency of the power supplied to the motor. A BLDC motor outperforms a brushed DC motor because it replaces the mechanical commutation unit with an electronic one, which improves dynamic characteristics, increases efficiency, and reduces noise levels slightly. Hall sensors are used to provide feedback to the motor controller. BLDC motors can operate more efficiently and accurately by using Hall sensors to detect the position of the rotor. There are typically three Hall sensors positioned around the stator. The sensors detect the position of the rotor’s magnetic poles as they pass by, and send a signal to the motor controller indicating which coil to energize next. The motor controller then switches the current to the appropriate coil, causing the rotor to continue turning. MATLAB/SIMULINK is used to examine the dynamic properties of BLDC motors, including speed, current, and back EMF.