Research On Optimal Design Of Full-bridge LLC Resonant Converter

The fluctuations in input voltage of new energy generation such as wind power and photovoltaic power generation and the demand for miniaturization of new energy vehicles have enabled the full-bridge LLC resonant converter to achieve high efficiency and high power density with its wide range of inputs.attention.This article mainly studies the full-bridge LLC resonant converter.This article first analyzes the working principle of the full-bridge LLC resonant converter.On this basis,the important parameters of the circuit and the influence and effect of the load resistance are further analyzed,and supplemented the equivalent model of LLC converter under the influence of high buck ratio leakage inductance.Based on the above derivation and analysis,this chapter presents a design scheme for the optimization parameters based on the load range.Secondly,this paper discusses in detail the hybrid control strategy applicable to the full-bridge LLC resonant converter,including time domain analysis in frequency conversion mode,time domain analysis in phase shift mode,and switching point selection for hybrid control.Based on this,the soft switching implementation conditions based on the load range in the frequency conversion mode and the soft switching implementation conditions based on the maximum phase shift angle in the phase shift mode are proposed.Furthermore,the hybrid variable frequency-phase shifting control strategy is further analyzed,so as to achieve high efficiency of the converter over a wide range of input and load ranges.Finally,based on the analysis of appeal theory,the overall system design of the full-bridge LLC resonant converter is carried out in this paper,including the main circuit parameter design and selection,the peripheral hardware design of the control system and the software design of the control system.This article simulates the experimental scheme,and further builds an experimental prototype to verify the correctness of the experimental scheme.This design scheme can guarantee a wide range of input voltage on the one hand,and guarantee higher efficiency of the converter based on the load range on the other hand.