Research On Three-phase LLC Resonant Converter Based On Hydrogen Production Power Supply

Traditional fossil energy is not renewable,and the large-scale use of traditional fossil energy poses a threat to its depletion.The combustion of fossil energy brings environmental pollution,seriously threatening the sustainable development of humanity.Hydrogen energy,as a clean and efficient secondary energy source,not only has high efficiency in converting into electricity and heat,but also has a wide range of sources for obtaining hydrogen energy.By extracting renewable energy,large-scale hydrogen energy can be obtained,which can then be converted into electricity or other forms of green liquid fuel through hydrogen fuel cells,thereby achieving a sustainable cycle of renewable energy replacing traditional fossil fuels and giving birth to a sustainable hydrogen economy.Electrolysis of water to produce hydrogen can achieve clean and sustainable production of hydrogen,and is one of the important preparation methods for producing green hydrogen.Therefore,developing efficient and stable power modules is of great significance.Considering the overall high power of the hydrogen production power supply and the high requirements for output current ripple,in order to improve the efficiency of the hydrogen production power supply and meet the requirements of low current ripple,this paper adopts a three-phase LLC topology and proposes a transformer secondary side rectification parallel topology based on the three-phase LLC topology.This topology not only achieves wide range adjustment of output current but also has significant advantages in reducing current ripple.Firstly,this article analyzes the working principle of the proposed rectifier parallel three-phase LLC topology and discusses its advantages in hydrogen production power supply applications;The basic operating characteristics of the three-phase LLC resonant converter topology were analyzed using fundamental wave analysis method.Based on this,the changes in voltage gain curve and the necessary conditions for achieving soft switching were studied.At the same time,the parameters of the resonant component and the main circuit were reasonably calculated by analyzing the voltage gain curve.According to the parameter requirements of the hydrogen production power supply,magnetic component design and device selection have been completed.Secondly,the soft switching characteristics of the switching transistor are achieved through frequency modulation control over a wide voltage and load range,while achieving wide range adjustment of the output current.The output voltage of the converter is adjusted through voltage closed-loop control.Finally,in order to verify that the proposed rectifier parallel three-phase LLC resonant converter has greater advantages in reducing output current ripple and wide range adjustment of output current,a simulation study of the three-phase LLC resonant converter was completed using PLECS power electronics simulation software to verify the dynamic response of the converter and the implementation of soft switching,The hardware circuit of the converter was designed and a experimental prototype was built to further verify the performance of the converter.