Nonlinear controller design for switched reluctance drive systems

A nonlinear speed-loop controller for a switched reluctance motor (SRM) drive system is proposed. The details of the controller design and analysis are discussed. In addition, to extend the controllable speed range, the commutating angle of the drive system is suitably adjusted as the motor speed goes beyond base-speed. 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 system has satisfactory performance in both the pulsewidth modulated (PWM) region and the single pulse region. The adjustable speed range of the system is from 10 r/min to 3000 r/min. In addition, the proposed drive system performs well in tracking ability, load disturbance rejection capability, and robustness. Several experimental results are presented to validate the theoretic analysis.