| This thesis focuses on the research of phase-shift full bridge zero-voltage-switching(PS-FB-ZVS) converter and its digital control technology. The detailed analysis of thesoft-switching and digital control technique, and the key problems of the PS-FB-ZVSconverterareproposed,thesimulationsandexperimentsarealsogiven.The PS-FB-ZVS converter is widely used in the case of medium orhigh power levels,and it's a hotspot of power electronic research. The two arms of which all work atzero-voltage switching condition, thus many advantages are brought out. For example,simple structure, little loss of power, convenient control, etc. But there also exists someproblems, such as inherent duty cycle loss and the parasitic oscillation on the outputrectifier diodes. In this paper, the reasons of theseproblems are analyzed, and the solutionsarepresented.In this paper, a novel ZVS converter topologyis proposed which adopts two clampingdiodes in the first side of transformer, thus the parasitic oscillation is eliminated. Theoperation principle of the novel converter is described in reason for the first time and thedesignmethodofcomponentparameter ispresentedandsimulatedby OrCAD/PSpice.On the other hand, with the advent of microprocessor, there has been an increasinginterest indigital control of switchmodepowersupply,insteadofanalogcontrol. Basedonthe state space theory and small-signal model analysis of this topology, this paperintroducesadigitalcontrolsystem,inwhichadigitalsignalprocessorIC(TMS320F240)isused as the core.This paper analyses the system control loop to satisfythe performance oftheconverterandalsopresents adesignmethodof digitalPIcontroller.The experimental resultsfrom a 5.5kWprototype converterindicate that: main circuit'sparameterisright andZero-voltage-switchingisachieved correctly; theparasiticoscillationon the output rectifier diodesis almosteliminated; the software works properly andfulfillsallfunctions.Thus thecorrectnessand availabilityofthedesignisvalidated.
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