宽增益高效谐振型直流变换器技术

Wide gain and high efficiency resonant DC-DC converter technology

直流变换器广泛应用于电动汽车充电系统与光伏发电系统,如何适应输入/输出电压大范围变化,实现直流变换器的宽增益和高传输效率为学术界和工业界所关注。其中,LLC、LLC_LC、LLCLC谐振变换器虽具有高功率密度、低电磁干扰等特性,但存在磁元件与谐振网络参数设计难度大,造成变换器输出不稳定等不足,难以满足实际应用的要求。为此,提出了宽增益高效谐振型直流变换器技术。首先总结了谐振型直流变换器的基本原理,围绕其拓扑结构及调制策略的国内外研究进展,重点就宽增益与高效谐振型直流变换器应用需求进行阐述。然后分析了LLC_LC、LLCLC多模式PWM倍压整流变换器拓扑及调制策略。最后结合仿真与实验验证结果,证明了该宽增益高效谐振型直流变换器拓扑及其调制策略的有效性,最高可实现输出电压范围为1~6.2,转换效率达96.1%,具有较宽广的应用前景。

The DC-DC converter is widely used in electric vehicle charging and the photovoltaic power generation system.How to adapt to input/output voltage changes over a wide range,and realize the wide gain and maximum transmission efficiency have attracted attention from academia and industry.Especially,since the LLC and LLC_LC as well as the LLCLC resonant converter have characteristics such as high-power density and low electromagnetic interference,there are shortcomings including difficulty in designing magnetic components and resonant network parameters.These cause instability for the converter output,and it is difficult to meet the requirements for practical application.Thus a wide gain and high efficiency resonant DC-DC converter technology is proposed.The fundamental principle of the resonant DC-DC converter is summarized.Then research progress,both domestic and abroad,for topology and modulation strategy,is examined.The paper elaborates the application requirement for a wide gain and high efficiency resonant DC-DC converter.Then the topology and modulation strategy for both LLC_LC and LLCLC with multi-mode PWM voltage�multiplying rectifying converter are analyzed.Through simulation and experimental verification,the effectiveness of the topology and modulation strategy for two wide gain and high efficiency resonant DC-DC converters is verified,to show a maximum output voltage range of 1~6.2,and a conversion efficiency of 96.1%.This shows good prospects for application.