SIMULATION OF BLDC MOTOR CONTROL USING SLIDING MODE CONTROL TECHNIQUE

Mostly, Brushless DC motors have been used in various industrial and domestic applications because of its advantages like simple structure, large torque, long use time, good speed regulation. Generally the BLDCM systems have uncertain and nonlinear characteristics which degrade performance of controllers. Based on these reasons, Sliding Mode Control (SMC) is one of the popular control strategies to deal with the nonlinear uncertain system. In This work implemented a SMC scheme for effective speed tracking by obtaining ripple free torque through the inner loop current control for a BLDCM. The second order mathematical model of the BLDCM is developed for simulation purposes. Two first order sliding controllers based on the exponential reaching law algorithm are developed for the inner loop current control and also for outer loop speed control of the drive. Performance of the speed tracking is then compared with a classical PI (Proportional and Integral) controller implemented for the speed loop and the advantages of the sliding mode scheme related with reduction of steady state error, settling time, percentage overshoot and disturbance rejection.This scheme is robust against the parameters variations. This work has been carried out with simulation studies using MATLAB2009