Research On Single Four-quadrant Power Switch Mode Current Source AC/AC Converter With High Frequency AC Link

The present status,development trend and application field of AC/AC converters are firstly presented in the thesis.Then novel circuit structure and circuit topologies family of current source 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 circuit topologies family include single four-quadrant power switch mode,push-pull mode,half-bridge mode,and full-bridge mode circuits. Taking single four-quadrant power switch mode circuit as an example,the operational mode,steady principles,transient voltage feedback control strategy,the auxiliary switching power supply and parallel technology of this kind of converters are investigated. The output characteristic curve and the design for the key circuit parameters are given. The current source 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,good line current waveform,strong load adapting ability and suit for low power conversion fields. The correction and advance of these converters are verified by the simulation and test results.