Position-Sensorless Hybrid Sliding-Mode Control of Electric Vehicles With Brushless DC Motor

This paper proposes an efficient and robust control scheme for the position-sensorless electric vehicle (EV) with a brushless dc motor. The back electromotive force detection method is first adopted and improved to implement sensorless control of the motor. The equivalent circuits of the control system are depicted, and the mathematical models under normal driving and energy regeneration are then derived, respectively. By combining the advantages of nonsingular terminal sliding mode with the high-order sliding-mode method, a hybrid terminal sliding-mode (HTSM) control scheme for EV is put forward to guarantee both system performance and robust stability. Experimental results show that the scheme can perfectly implement position-sensorless control without Hall sensors and that the HTSM exhibits better performance and higher efficiency than the proportional-integral-differential (PID) controller. Furthermore, more energy is recovered, and by the proposed scheme, the driving range is improved 5.7% more than using the traditional controller.