Comparison of PI and Fuzzy logic DC-Link Voltage Controller for DPC PWM-Rectifier

This paper treats direct power control (DPC) for three-phase PWM rectifiers using a new switching table, without line voltage sensors and the fuzzy logic theory. The instantaneous active and reactive powers, directly controlled by selecting the optimum state of the converter, are used as the PWM control variables instead of the phase line currents being used. 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 with maintain the dc-bus voltage at the required level. Conventional PI and a designed fuzzy logic-based controller, in the dc-bus voltage control loop, have been used to provide active power command. A digital simulation, in Matlab/simulink, was carried. The steady-state and dynamic results illustrating the operation and performance of the proposed control scheme are presented. As a result, it was confirmed that the novel DPC is much better than the classical one. Simulation results show clearly the effectiveness of the adopted control strategies.