Design of Fuzzy Logic Controller for Speed Control of Sensorless BLDC Motor Drive

Brushless Direct Current (BLDC) motors are employed in fans called super fans, electric and hybrid vehicles, industrial automation as actuators for industrial robots, extruder drive motors and feed drives for Computer Numerical Control (CNC) machine tools and home appliances. A BLDC drive consists of a six switch inverter and Hall Effect position sensors. The speed regulation of sensorless BLDC drive using four-switch three-phase inverter BLDC motor and fuzzy controller is proposed here. As there are no sensors and due to reduced inverter switches, cost of the drive is less. This system focuses on Back Electromotive Force (EMF) difference zero crossing approximation technique which reduces the difficulty of designing filters in back EMF zero crossing detection method. The MATLAB simulation model and hardware results are given to validate the novelty of the circuit and a fuzzy logic controller regulates the speed.