Research On Full-bridge Mode Current Mode AC/AC Converter With High Frequency AC Link

The present status and development trend of AC/AC converters are firstly presented in the thesis.Then novel circuit structure and circuit topologies family of current mode AC/AC converters with high frequency ac link,based on Flyback converter,are proposed. The circuit structure which can transfer one unregulated sinusoidal voltage with high THD into another regulated constant frequency sinusoidal voltage with low THD is constituted of input cycloconverter,high frequency storage transformer,output cycloconverter,input and output filter. The topologies family include single four-quadrant power switch mode,push-pull mode,half-bridge mode,and full-bridge mode circuits. Taking full-bridge mode circuit as an example,the operational mode,steady principles,transient voltage feedback control strategy of the converter are investigated. The output characteristic curve,the design for the key circuit parameters and the reference sinusoidal circuit which is synchronous with the signal of n or 1/n times line voltage frequency are given. The current mode AC/AC variable frequency converters with high frequency ac link are also presented in the thesisThe current mode AC/AC converters with high frequency ac link have the advantages such as simple topology,two-stage power conversions,bidirectional power flow,high frequency electrical isolation,strong load adapting ability,suit for low power conversion fields. The correction and advance of these converters are verified by the simulation and test results.