Improvement of PWM Rectifier Performances Using Direct Power Control and Fuzzy Logic Theory

The study made in this paper concerns the use of the direct power control (DPC) technique and the fuzzy logic theory to control a pulse width modulation (PWM) rectifier. These strategies are used to eliminate harmonics currents and consequently to reduce total harmonic distortion (THD) of the line current and improve the power factor. The DPC principle is based on the control of instantaneous active and reactive powers. 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. With the aim of ensuring a stable active power exchange, a fuzzy inference system is adopted for the DC voltage control. A digital simulation, in Matlab/Simulink/ SimPowerSystems and Fuzzy Logic Toolbox, was carried out and given in the end of this paper. Simulation results show clearly the effectiveness of the of the adopted control strategies.