Performance Improvement of Sliding Mode Controller of BLDC Drive for EV Applications

BLDC motors are becoming popular in low and medium power drive applications, position control, and also servo applications. Because of its very smooth speed control within a specified limit, high efficiency, and low maintenance cost, this motor is widely accepted for wide range of applications. The motor has excellent linear speed torque characteristics for an electromechanical actuator. It is possible to achieve a good speed response from the machine using simple control theory. The various control principles used in BLDC motor drives to control the speed and currents, necessitate extremely complex calculations, so DSP controllers must be incorporated. This will significantly increase the system's cost. In this study, a simple but cost-effective solution for improving the performance of a BLDC motor is proposed. The scheme employs a digital on-off or hysteresis band controller that is based on simple logic. This study also includes hardware implementation, which is based on a low - cost microcontroller.