MODELLING, SIMULATION AND HARDWARE IMPLEMENTAION OF SPEED CONTROL OF BRUSHLESS DC MOTOR

Abstract

Permanent Magnet Brushless DC (PMBLDC) motor belongs to the class of special electrical machines. Brushless DC motors offer many attractive features like low maintenance, fast response, noiseless operation, high efficiency, high power density, good reliability and compact construction. The inherent simplicity, ruggedness and high efficiency make it a viable machine for various general purpose adjustable speed drive applications. As a result, the brushless DC motors are increasingly being used in military, industrial and commercial applications. Its market is rapidly expanding. Performance enhancement of BLDC motor drive is an essential task for the researchers today. Initially a mathematical model of BLDC motor is presented. It is assumed to be a linear model. This project presents developed model of Brushless DC Motor by using MATLAB/Simulink and performance characteristics of motor are observed during various loading conditions. Simulation results obtained from developed model are discussed. A conventional six switch BLDC motor drive system was studied and simulated. In this research work, various strategies have been adopted to improve the performance of BLDC motor. The different strategies adopted in this research work include design of PI, hysteresis current controller. The hysteresis current controller is implemented with speed feedback loop and it is observed that torque ripples are minimized. In this method the current (or torque) ripple can be restricted within the predefined band-gap Simulation is carried out using MATLAB / SIMULINK. The results show that the performance of BLDCM is quite satisfactory for various loading conditions. The hardware project is designed to control the speed of a BLDC motor. The objective of this work is to control the BLDC motor automatically through microcontroller. A microcontroller based speed control scheme has been developed. The microcontroller has been programmed in such a way that when the duty cycle is varied, speed is changing. Also the implementation of motoring mode is carried out and the results are shown in digital storage oscilloscope.