Speed Control of Brushless DC Motor Using PI Controller with Fuzzy Logic

The brushless direct current (BLDC) motor is an DC voltage-fed, electrically commutated motor. As implied by its name, it does not contain brushes for commutation. An BLDC motor comprises a permanent magnet rotor and stator in form of multi-phase armature windings. Better efficiency compared to brushed motor, high power-to-weight ratio, better speed-torque characteristics, noiseless operation, and long durability due to a lack of frictional loss and electrical losses makes it a pioneer in the electric vehicle (EV) industry and other small to large-scale industries. The construction is similar to a permanent magnet synchronous motor (PMSM) but with a trapezoidal back EMF waveform. In this proposed model, a DC voltage source, upon applying through an inverter circuit and with feedback signals provided by Hall sensors, with a unique commutation logic, is used to energize the pole pairs so as to achieve a unidirectional torque in the rotor. A combination of PI controller and fuzzy logic controller is used to stabilize various dynamic characteristics. Different dynamic characteristics such as torque and speed back EMF are analysed using MATLAB Simulink model of the BLDC motor and the electronic speed controller (ESC).