Research On Predictive Control Of Single Phase Full Bridge Soft Switched PFC Converter

As the amounts of electronic equipment in the grid increasing, the problem ofharmonics pollution have been taken seriously. In order to solve this problem, thepower factor correction technoloy is applied to the electronic equipment. Activepower factor correction technology is under a profound study and appliction, for itsoutstanding performance and undeveloped potential. Two of the research focus areconverter topology and control method.Full bridge boost converter has the advantages of co ntinuous input current andgalvanic isolation, when used as power factor correction converter. Due to theprimary transformer leakage inductance, large voltage spike will appears across thetransistor when the transistor is turned off. The probability of transistor damagelimited the application of FB boost coverter. This thesis proposes a soft switched FBboost converter on the ground of a study of many existed soft switched FB boostconverter. The proposed converter can be switched softly with a proper switch order,without the need of an auxiliary transisitor, and the converter can be controled byPWM method.The control objective of a power factor correction converter is to force theinput current following a sine reference current which is with the same frequencyand phase with the grid voltage. More and more control method can be applied dueto the development of digital control technology. Prective current control offers thepotential for achieving the fastest transient response, which overwhelming nor malaverage current control and one circle control, and has been widely studied. In thisthesis, predictive vally current control of boost type PFC converter is analyzed,which is focused on the effects of model error on the current control performance.An simple feedback compensation is proposed to assist the predictive control whenlow frequency model error exists.In this thesis, the converter state variety over the grid circle is analysised usingaveraged large signal modle, and the effects of input ind uctance on the ability ofcurrent following is studied. Detailed characteristic selection progress of maincircuit and resonant circuit is included. An experimental prototype is built to verifythe analysis.