Research On LC Series Resonant Converter Based On AC-Link

Fossil fuels meet the needs of a large amount of energy for the development of human society,but with the reduction of fossil fuel reserves and the serious impact on the ecological environment,human beings must find inexhaustible clean energy.Solar energy,wind energy and other new energy sources have received widespread attention,and more and more researchers and funds have been injected into the research and industry of new energy sources.New energy is mainly converted into electricity through power electronic devices for use,so power electronic technology has been flourishing and developing.In this thesis,the resonant converter in the field of power electronics technology is studied in depth.Firstly,four kinds of resonant converters widely used in DC-Link technology are investigated;the converters based on AC-Link with resonant structure are investigated in detail at home and abroad;and the state-plane analysis method for the analysis of various resonant converters is investigated.In DC-Link LC series resonant step-up and step-down converter topology,a controllable switch tube is added to the secondary rectifier output unit,and energy is stored and released by the short-circuit secondary transformer in order to realize the function of widening the input voltage range.This method is introduced into the topology of AC-Link LC series resonant converter.The working process of step-down mode and step-up mode of the resonant converter are analyzed in detail.The state plans of the two modes are deduced.Based on the state plane analysis method,the working process of the step-up mode and step-down mode of the converter is analyzed and solved,and the two modes are deduced.Control algorithmThe simulation model of AC-Link LC series resonant converter is built in Simulink,and the control algorithm of the two modes is simulated and analyzed.The simulation results show that the power factor of the converter is above 0.99 under boost and buck modes,with a high power factor.The total harmonic distortion rate of the input current is maintained at about 3.1%,and the output voltage is stable and the ripple is small.The feasibility of the control algorithm.Based on the DSP control system,the experimental scheme of AC-Link LC series resonant converter is designed.The overall control idea of the experiment is given,and the design ideas of some important hardware circuits and software programs are given to verify the correctness of the control algorithm.