Impedance Network Matching Mechanism And Design Of Z-network Converters

Power electronic is to control the power conversion between various forms and/orcharacteristics to suit particular applications, so the design of power converters is the mostimportant and basic work. From the perspective of impedance networks, the impedancenetworks on power converters are studied. Then, an impedance network matching mechanismand a systematic method to design Z-source converters are proposed. Finally, four novelconverters are designed by this method. The contributions of the thesis are shown as follows.(1) From the perspective of impedance networks theory, the limitations of traditionalconverters, and the unique features of Z-source converters are analyzed to further understandthe formation of impedance source converters.(2) An impedance network matching mechanism and a systematic method are firstlyproposed to improve power converters by adapting parameters, and design novel impedancesource converters, which promots the development of impedance source converters.(3) According to the proposed design method, two novel3-Z-network DC-DC Boostconverters with350of voltage gain are proposed to solve the limited voltage problem in solarenergy systems. Concretely, three active impedance networks are cascaded to make the outputimpedance being negative, and then realize the high voltage by output impedance matching.(4) According to the proposed design method, a novel Z-source half-bridge converter isproposed to realize the desired output votage in electrochemistry power systems and solve themidvoltage problem. Concretely, a Z-network is inserted into a half-bridge converter toincrease the input impedance to realize input impedance matching.(5) According to the proposed design method, a novel dual-output Z-source half-bridgeconverter is proposed to reduce the economic cost and increase the power density in electricvehicle systems. Concretely, two converters are paralled to decrease the output impedance,and then one forth of switches and capacitors are reduced to realize the simplest structure ofthe converter.The creativity of the thesis is to deeply anlyze Z-source converters from a newperspective and then propose a general design method of impedance source converters, whichpromotes the systematic design of power converters, and which are of great theoreticalsignificance and practical applications.