A Combined Second-Order-Generalized-Integrator Based FLL and Two-Degree-of-Freedom PID Current Control scheme with Quintic Torque Sharing Function for Torque Ripple Minimization in SRM Drives

The purpose of this study is to describe a current control strategy for reducing torque ripple in a 6/4 three-phase switched reluctance motor (SRM). The proposed current control approach consists of a second-order-generalized-integrator (SOGI) based on frequency-locked-loop (FLL) controller and a two-degrees-of-freedom (2DOF) PID controller. To lessen the current harmonic components, a second-order-generalized- integrator-based FLL is introduced in parallel with a traditional proportional-integral (PI) controller. When attempting to reduce the effects of current harmonics, the SOGI-based FLL current controller may cause overshoot in the current loop response. A PID controller with 2DOF is introduced to reduce overshoot. Combining a 2DOF-PID controller with a SOGI-based FLL controller yields a SOGI-FLL-2DOF PID current controller. Compared to conventional hysteresis and proportional-integral (PI) current controllers, the proposed SOGI-FLL-2DOF PID current controller reduces overshoot and torque ripple in addition to suppressing current harmonics. In contrast to previously known cubic torque sharing functions(TSF), The cubic TSF provides constant locations and velocities in the turn-on angle and overlap angle zone but discontinuous acceleration. We provide a TSF based on a fifth-order quintic polynomial that meets smoothness and boundary criteria easily. This paper evaluates the steady-state performance for torque ripple based on simulation modelling and experimental data, and it also recommends the feasibility of using the SOGI-FLL-2DOF PID current controller to an SRM and provides some guidelines for doing so.