Disturbance Observer-based Stable-current Control Algorithms for The Electrolytic Power Rectifiers

At present, power diode rectifiers with self saturated reactors used in electrolytic industrial environment are plagued by the anode effects trip. A robust control strategy based on disturbance observer is presented. The disturbance observer estimates the disturbance (anode effects, sensor noise etc.) using a nominal model and compensates for the parameter variations between the real model and the nominal model. First, a model is proposed for the commonly used 3-phase controlled rectifier, and the corresponding circuit equations are derived. Next, a design method for disturbance observer is presented. Finally, the experimental results from an implementation of the proposed method are presented