Real-time fuzzy control of a three-phase phase-controlled rectifier operating in discontinuous conduction mode

This paper presents a fuzzy feedback control system for DC voltage regulation of a phase-controlled three-phase rectifier. The controller operating range covers both the continuous conduction mode and the discontinuous conduction mode. In the latter operating region, the converter characteristics are highly nonlinear and too difficult to be modeled mathematically. For this reason, a fuzzy control design based on a heuristic representation of the process is proposed. The digital model of the controller is, first, established using the Fuzzy toolbox of Matlab/Simulink, then compiled in the OPAL RT-Lab OP4100 special device that allows real-time control. For experimental validation, the designed fuzzy controller is applied to a 3 kW laboratory prototype three-phase thyristor-bridge feeding an inductive load. The tracking and regulation performances of the control system are tested, and the corresponding data are plotted.