Torque ripple optimization of switched reluctance motor using two-phase model and optimization search techniques

Torque ripple optimization scheme for SRM drive, based on fibonacci and exhaustive search method and 2-phase excitation model of SRM has been presented in this paper. The 2-phase excitation model of SRM used here takes into account the nonlinear effects because of saturation and mutual flux linkages caused by multi-phase excitation. In the proposed scheme the incoming and outgoing phase currents are modulated to minimize the torque ripple. Because of the highly nonlinear nature of torque, fibonacci and exhaustive search methods are used for optimizing the torque ripple, by simulating the model multiple times. Modulation of phase current is done by addition, subtraction and multiplication of constants and variables. This can be very easily achieved in DSP micro-controllers and FPGAs. Simulation and hardware results are presented for proposed optimization scheme and compared with constant current operation. It has been shown by simulations, that the proposed optimization scheme reduces the torque ripple by more than 50% as compared to traditional constant current scheme. The proposed optimization scheme has been experimentally validated. The experimental results show that the torque ripple is reduced by 49% to 45% for a reference current of 8A and 10A as compared to the constant current case.