Research And Implementation Of AC-DC Matrix Converter

A new type three-phase AC-DC converter topology is achieved by transforming3-phase to3-phase matrix converter, which permits AC-DC conversion without large reactive energy storagecomponent.The input fundamental displacement factor approachs nearly unity. This converterattracts scholars home and abroad in recent yeas.This dissertation firstly introduces the fundamental elements and modulation methods ofAC-DC matrix converter.By comparing different modulation patterns, an optimized strategy ispresented. Expressions of output voltage and input current under this modulation strategy arederived. Meanwhile, the power factor control method is adopted to analyze in detail, which isproposed and built in dq synchronous rotating frame based on the grid voltage vector,whichincreases power factor of input by changing the modulation vector.The simulation model is constructed on the Matlab software platform and a series ofsimulations are made under different outputs, which is used to compare input voltage and current.Simulation results validate correctness and feasibility of the theory and control strategy proposedin this paper.The design of AC-DC matrix converter with closed loop control is introduced, includinghardware and software. Hardware consists of high frequency transformer and other functionalcircuits. Software program is formed by DSP and CPLD.Finally, a series of experiments are done on the platform of AC-DC matrix converter, theresults show that the input current is in phase with the input voltage with power factor control,which validates the proposed modulation strategy for AC-DC matrix converter is correct andfeasible.