A Novel Control Strategy Of High-frequency Link Inverter

These days,with the development of distributed generation high-frequency link inverter becomes more and more attractive because of the advantages of small volume,high power density and high efficiency.A novel control strategy for the common full-bridge bridge-formed high frequency link inverter topology is proposed,which could realize switches' soft-switching,cycloconverter's soft commutation and improve the working reliability of high-frequency link inverter.Firstly,the developing history and trends of high-frequency link inverters are introduced.And then the state of art in foreign and domestic is summarized to express the necessity of the research of high-frequency link inverter.Secondly,a novel control strategy has been designed based on the full-bridged bridge-formed topology.The detailed analyses of the inverter's working states and equivalent circuits in different operating modes have been made.What's more,the inverter's per-unit properties and soft-switching conditions have been discussed and demonstrated.Thirdly,the mathematical models of first full-bridge stage and second cycloconverter stage have been built through the high-frequency link inverter's working principle.According to the analyses of the models the illustration of working principles and process has been given.And simulation results have been presented to prove the correctness of the above analyses.Fourthly,research about the close-looped control strategy has been done in this paper.A double-close-looped control model has been built and the parameters of the double-close-looped controller have been given.Furthermore,a simulation model has been built to prove the effectiveness of the close-looped control strategy.Finally,1kW simulation model and prototype are presented.And the validation experiment has been carried out in the prototype.The waveforms of experimental results and its analyses have been given to prove the effectiveness of the novel strategy.