Speed control of BLDC motor using fuzzy logic controller based on sensorless technique

Brushless dc (BLDC) motors are very popular and are replacing brush motors in numerous applications due to its superior electrical and mechanical characteristics owing to its trouble free construction. This paper presents the BLDC motor sensorless speed control system with fuzzy logic implementation. The sensorless techniques based on the back EMF sensing and the rotor position detection with a high starting torque is suggested. The rotor position is aligned at standstill for without an additional sensor. Also, the stator current can be easily adjusted by modulating the pulse width of the switching devices during alignment which will be helpful to reduce cost and complexity of the drive system without compromising the performance. The design analysis and simulation of the proposed system is done using MATLAB version 2010a and the simulation results of sensored drive using PI controller and sensorless drive using proposed methods are analyzed.