Modelling Analysis And Control System Design Of Three-phase PFC Rectifier

Power factor correction technique is an effective way to improve the reliability and electric power quality of grid,which has become a popular research area in switching power supply.Currently,single-phase PFC technique has been maturely developed.However,as for high-power application,three-phase PFC technique applying for three-phase equipment are still calling for the technical solution.To reduce the harmonics of the power grid and improve the power factor,it is necessary to discuss the system characteristics analytically and design the corresponding controller for such three-phase PFC system,which is the effective way to improve the system performance.For such purpose,a three-phase four-wire VIENNA rectifier and a three-phase six-switch PFC rectifier are chosen as the plants in this dissertation.Focusing on the theoretical modeling,control system design,simulation and experiment validation of two kinds of three-phase PFC rectifiers,the discussed three-phase PFC rectifiers using the proposed control methods have the advantages of high power density,small size,easy control and high power factor.The main results of this dissertation are as follows:1.The analytical mathematical models of three-phase VIENNA rectifier and three-phase six-switch rectifier are discussed by using the state space averaging method.The proposed models can be used for the theoretical analysis and controller design.2.Design the overall hardware system of three-phase PFC rectifiers,including the main power circuit design,auxiliary power supply circuit design,sample circuit design and driving circuit design.Following the rules,using less device design scheme and the small size devices,the designed hardware systems can reduce the power supply size effectively.3.The average current control method is used for the three-phase four-wire VIENNA rectifier.Keeping high power factor,this structure is easy to implement in the real application.For the three-phase six-switch rectifier,SVPWM control method is used.Considering the coupling between three-phases,the SVPWM control method can achieve decoupling adjustment,which is the key to ensure good dynamic characteristics and accuracy.To verify the effectiveness of the proposed methods,the three-phase VIENNA rectifier and three-phase six-switch rectifier simulation analysis by PSIM software and experiment platform results are given in this dissertation.