Sensorless Speed Control of Switched Reluctance Drives Using a Nonlinear Controller

This paper proposes a nonlinear speed-loop controller for sensorless control of a switched reluctance motor (SRM). By on-line estimating the self-inductances of the motor, the shaft position and speed of the SRM is obtained. A simple nonlinear controller can compensate for speed-estimation error and parameter variations is derived from a Lyapunov function. Then, a closed-loop sensorless drive system can thus be achieved. The details of the sensorless technique and the controller design are discussed. By using a 32-bit microprocessor, a fully digital drive system including a digital speed-loop controller and a digital current-loop controller is implemented here. The hardware circuit of the drive system is very simple. The proposed drive system performs well in speed responses, load disturbance rejection capability, and robustness. Several experimental results are presented in the paper to validate the theoretic analysis.