Speed control of Brushless DC motor in discrete delta domain: A unified approach

Electronic commutation, not brushes, powers a brushless DC motor (BLDC). It is used in HVAC, electric automobiles, industrial automation, and robotics. BLDC motors don't have brushes; thus, they last longer and need less maintenance. Speed control improves energy efficiency, performance, torque output, and noise. In this digital era, controllers must be discrete to avoid compromising system performance. If a continuous time controller is discretized using shift operator parameterization and exposed to high sampling frequency, it fails to provide meaningful results. In other hand, discrete controller design using delta operator parameterization overcomes the drawbacks of discretization using shift operator parameterization. In this paper the speed controller of BLDC motor is realized using delta operator parameterization and the discrete controller deigned in delta domain provides the same result as can be obtained using the corresponding continuous time controller, at very fast sampling rate. The performance of the discrete delta domain-based controller is compared with the performance of the discrete shift operator-based controller and continuous time controller, and the simulation results show that at a very fast sampling rate, the delta domain discrete controller outperforms the shift operator based discrete controller. The MATLAB /Simulink is used to get the results.