Backstepping nonlinear speed controller for switched-reluctance motors

The application of the backstepping feedback design technique to the speed control of a switched reluctance motor (SRM) is investigated. Using this backstepping method, both feedback laws and Lyapunov-based designs are applied in the controller design. The mathematical model for the SRM takes magnetic saturation into account. The controller takes phase currents and voltages, rotor position, rotor speed and reference speed as inputs, and calculates the phase current required to maintain the motor speed close to the reference speed. The excitation angles are continuously controlled to improve the system performance. An experimentally verified Saber model is used for simulation studies and a 20 kW SRM drive prototype is built to study the performance of the proposed controller. A conventional PI controller is used for comparison. Both simulation and experimental results show improved transient and steady state performance, and robustness of the nonlinear controller.