Research On V~2C Controlled Dual Output SWISS Rectifier

With the development of new energy in China becoming more and more intelligent,interconnected and more stringent requirements for environmental protection,blade electric vehicles is the main direction of the development of vehicle types in the future,and improving the scale and efficiency of supporting charging equipment for electric vehicles is also a top priority.This thesis is based on a three-phase step-down PFC circuit(SWISS rectifier)for electric vehicle charging,which has the characteristics of low switching loss,strong voltage output adjustment ability and high power factor.After analyzing its basic working principle and control strategy,this thesis looks for a better control method to improve its output waveform quality and response speed.At the same time,its topology is improved to realize the dual output function of SWISS rectifier.Firstly,this thesis summarizes the basic structure and working principle of SWISS rectifier.The current space vector control and harmonic injection network control are studied,the injection current minimization control and inductance current minimization control are emphatically analyzed,and the equivalent circuit model of SWISS rectifier is deduced,which provides a theoretical basis for the following research on new control algorithm and dual output structure topology.Secondly,this thesis improves the double closed-loop control of traditional SWISS rectifier.A V~2C control with filter capacitor voltage,inductor current and output voltage as feedback control quantity is adopted.After studying its working principle,the small signal model of V~2C controlled SWISS rectifier is established.By analyzing the Bode diagram of peak current control,V~2 control and V~2C control,it is found that V~2C control combines the advantages of fast response speed of peak current control and strong anti-interference ability of V~2 control.The fast response characteristics and good anti-interference performance of V~2C control are verified based on the simulation results of MATLAB/Simulink.Finally,this thesis adds a dual output topology to the basic structure of Swiss rectifier.Through the single inductor dual output structure and transformer coupling,the dual output function and electrical isolation function of Swiss rectifier are realized.The working principle of single inductor dual output Swiss rectifier is analyzed,and its equivalent circuit mathematical model is derived.Differential mode and common mode voltage modulation are selected to reduce the cross influence between the two output branches.PLECS simulation shows that the differential mode and common mode voltage modulation strategies can reduce the cross influence of the two output voltages,and the correctness of the conclusion is further determined through the hardware in the loop experimental platform.