This paper treats control strategies of a pulse width modulation (PWM) rectifier to eliminate harmonics currents and consequently to reduce total harmonic distortion of the line current and improve power factor. It is about the use of direct control principle to control instantaneous active and reactive powers. Such a technique is called direct power control (DPC). The principal idea of DPC was suggested initially by Ohnishi (1991) and developed then by Noguchi and Takahachi in 1998. This concept is similar to DTC applied to induction motors. A comparative study, concerning the DC voltage control, will be given in this study. It is about the use of a PI controller and a fuzzy logic one to ensure a stable active power exchange. A digital simulation, in Matlab/Simulink/SimPowerSystems and Fuzzy Logic Toolbox, was carried out and given in the end of this paper. The simulation results show clearly the supremacy of the technique adopted to control the DC voltage.
