Research On Control Strategy Of Three-phase VIENNA Rectifier

As an important interface between power grid and power equipment,three-phase rectifier has been widely used in aerospace,national defense,industrial manufacturing and other fields.As a new three-level circuit topology,three-phase VIENNA rectifier has the advantages of less switching devices,less switch stress,low cost,no dead time between driving signals,less harmonic content of current on the network side,etc.which has attracted the attention of scholars at home and abroad.Firstly,this thesis analyRes a variety of rectifier topologies,and determines the three-phase three-level VIENNA rectifier as the research object.This thesis analyRes the working principle of single-phase and three-phase VIENNA rectifier,describes the working characteristics of three-phase VIENNA rectifier in different switching states,and establishes the mathematical model of three-phase VIENNA rectifier in abc,αβ and dq coordinates.Secondly,based on the mathematical model of three-phase VIENNA rectifier,the control system is designed.Three phase VIENNA rectifier adopts traditional double closed-loop PI(Proportional Integral)control,which is difficult to realiRe Rero static error tracking regulation of input AC flow.At the same time,dq axis decoupling requires multiple coordinate transformations,which is not conducive to digital realiRation and will bring high-order harmonics to grid side current.Therefore,PR(Proportional Resonant)control and MPC(Model Predictive Control)control of current inner loop are studied.According to the definition of space vector,the basic vector distribution of three-phase VIENNA rectifier is derived.The implementation of space vector modulation of three-phase VIENNA rectifier is analyRed in detail.A simplified implementation method of transforming three-level space vector modulation into two-level space vector modulation is given.Finally,based on the above theoretical research,the three-phase VIENNA rectifier is simulated with Matlab/Simulink,and the experimental platform of three-phase VIENNA rectifier is built with STM32F103RCT6.Simulation and experimental results verify the rationality of the research.