Three-Phase High Power Factor PWM Rectifier And Its Control Strategy

The traditional control methods of rectifiers are phase-controlled rectifier and uncontrolled rectifier. The method of phase-controlled rectifier has a slowly dynamic response and a low power factor in net side when system works in deep control. The method of uncontrolled rectifier has some disadvantages as follow: The rectifier imbibes distortion current from the net side and brings harmonic wave to the net; the energy of the DC side can't feed back to the net side. The PWM rectifier can overcome the disadvantages of the phase-controlled and uncontrolled rectifier. It has a high power factor, low current harmonic wave, energy feedback and quickly dynamic response etc. These advantages make the PWM rectifier as an ideal interface of the electric appliance or electric net with other electric equipment.The article describes the three-phase voltage source PWM rectifier and its control system design. The MATLAB software is used to emulate the system.The paper introduces the theory of the three-phase voltage source high power factor PWM converting circuit and its simulation. The paper expatiats the voltage source PWM rectifier's mathematic model, work theory and control method. Based on this, the simulation of the voltage source rectifier and its control system has been finished by MATLAB software. Considering the control methods, there generalizs some control schemes that are popular in practice and analyse their feature. The paper introduces the two-loop control of the three-phase voltage source PWM rectifier based on the voltage space vector PWM(SVPWM) modulation and fuzzy logic control modulation, then comparing the two methods, it is easy to see that the new fuzzy logic control is better than the SVPWM.The paper verifies the correct of the control methods and system parameters design method of the tree-phase voltage source PWM rectifier by simulation, especially the fuzzy logic control method predigests the system calculation.