Design implementation and testing of a three phase BLDC motor controller

This paper intends to develop a three phase Y-connected Brushless DC (BLDC) motor controller by using low cost PIC 18f4431 microcontroller. Unlike a brushed DC motor, the commutation of a BLDC motor is controlled electronically. To rotate the BLDC motor, the stator windings should be energized in a sequence so it is important to know the rotor position in order to understand which winding will be energized following the energizing sequence. BLDC motor in this study has three Hall effect sensors embedded into the stator on the non-driving end of the motor to know the rotor position. The output of the three Hall effect sensors are feed to the PIC18F4431 microcontroller for generating six PWM signals with a predefined frequency where the required PWM is active and others are inactive. This motor has been tested using 35V power supply with a satisfactory result.