Digital R-S-T controller for current loop control of DC/DC buck converter: A photovoltaic (PV) array simulator under partial shading condition

Nowadays power electronics converter that uses for emulate electrical characteristic V-I curve of renewable dc power source are widely interested in research fields. This paper concerns with a photovoltaic (PV) array simulator using a classical dc/dc buck converter as power stage. The inductor current of the converter is used as control variable that is characterized by digital R-S-T controller, so the converter can emulate accurately the V-I curve, even under partial shading condition. Fundamental of controller design is presented with the technique of canceling discrete zero of plant. The details of PV array model are also investigated in order to prepare an appropriated current loop command signal. The design concept is realized by 330 Watts of prototype. Finally, the experimental results validate the proposed controller.