A robust speed controller for switched reluctance motor with nonlinear QFT design approach

Robustness and simplicity are necessary requirements for general purpose adjustable speed SRM drives and quantitative feedback theory is a powerful robust control design method in which trade-offs between control design objectives and considerations are very transparent. Due to special structure and switching operation, an SRM has highly nonlinear characteristics. In this paper, firstly the nonlinear characteristics of the motor are replaced with equivalent disturbance and uncertainty. Then, QFT design is done for the equivalent model. The design is implemented on a 4 kW drive and simulation and experimental results show the effectiveness of this method in obtaining control objectives