Static-Errorless Deadbeat Predictive Current Control Using Second-Order Sliding-Mode Disturbance Observer for Induction Machine Drives

Although the conventional deadbeat predictive current control (DPCC) can theoretically provide fast current dynamic responses for induction machine (IM) drives, it suffers from problems of steady state current error and stability due to a detrimental model mismatch. To solve these problems, this paper proposes static-errorless DPCC using a second-order sliding-mode disturbance observer (DO). The IM parameter variation and other unmodeled dynamics are regarded as lump disturbance in the modeling of IM. Based on this model, a second-order sliding-mode DO is constructed to estimate lump disturbance, and then the estimated disturbance is applied as feed-forward compensation to correct the steady state current error. Moreover, the designed second-order sliding-mode DO effectively alleviates the chattering effect caused by the switching control. Since the designed DO works in parallel with the DPCC, the fast dynamic responses of the DPCC is retained. Experimental results confirmed the validity of the proposed scheme.