An Improved Deadbeat Control Scheme for Unipolar Sinusoidal Current Excited Switched Reluctance Motor Drives

Abstract

This article reports on a novel deadbeat control (DBC) scheme to improve the current regulation performance of the unipolar sinusoidal excited control strategy for switched reluctance motors (SRMs). In this scheme, the deadbeat controller with delay compensation is first designed by using a second-order inductance-based SRM model in the rotating reference frame. This developed model can provide a more accurate description of the torque and electromagnet characteristics compared with the existing model. However, ignoring the magnetic saturation during the modeling inevitably leads to uncertainties in the proposed DBC system. To further estimate the disturbance caused by these uncertainties and improve robustness, a simple adaptive disturbance observer (ADO) based on the steepest descent method is embedded in the deadbeat controller. Then, a stability analysis based on the discrete-time Lyapunov function is used to guarantee convergence and tune the adaption gain of the proposed ADO. Finally, comparative experiments under different operation conditions are carried out on a three-phase 12/8 SRM prototype to verify the effectiveness of the proposed scheme.