Design of Speed Controller for a Brushless DC Motor using Feedback Linearization

Due to advancement in the research on permanent magnet materials, brushless DC motors have paved their way into the industry. An electric drive comprising of electronic circuitry and control algorithm is a core necessity to run such a motor. Drives based on conventional control techniques are often unable to provide desired performance, therefore advanced control techniques have been devised in literature based upon different mathematical models. Some of these are focused on accurate results while others aim for simplicity in implementation at the cost of accuracy. The techniques that promise accurate results are not easily implementable thus there exists a void for a control technique that is easy to implement and offers fairly accurate results. This paper presents a relatively simple but an accurate non-linear model of a brushless DC motor, furthermore feedback linearization is used to linearize the model then a state feedback control law is used to ensure tracking. To demonstrate accuracy of the proposed technique the designed controller is implemented in simulink and its results are presented.