Torque ripple minimization in SRM drive using second-order-generalized-integrator-based FLL equivalent PR current controller

A second-order-generalized-integrator (SOGI)-based frequency-locked-loop (FLL) equivalent proportional-resonant (PR) current controller is introduced in this paper to minimize torque ripple in switched reluctance motor (SRM) drive system. The typical cascaded closed-loop speed control of SRM comprises a speed controller giving desired torque, a static look-up table mapping the desired torque to desired/reference phase currents of SRM, and a current controller to track the reference phase currents. It is often seen that conventional current controllers like hysteresis controllers, proportional-integral (PI) controllers, and even intelligent controllers such as fuzzy logic controllers and model predictive direct torque controllers (MPDTC) are not very effective in minimizing the torque pulsations for a wide range of operating scenarios. The proposed SOGI-FLL-PR-based current control strategy is aimed at improving torque control under a wide range of operations of SRM. The performance of the proposed current controller has been compared to that of traditional current controllers like the hysteresis controller, the proportional-integral controller, the fuzzy logic current controller (FLCC), and MPDTC; and has shown to be superior in both simulation and experimental studies. Our study details a systematic approach to the dynamic modeling of SRMs, control strategy formulation, dynamic analysis, and experimental verification.