基于输入并联输出串联的高效高升压比DC-DC变换器  

High-Efficiency High Voltage Gain DC-DC Converter Based on Input Parallel and Output Series Connection

作　　者：桑汐坤 王懿杰[1] 徐殿国[1] Sang Xikun;WangYijie;Xu Dianguo(Department of Electrical Engineering Harbin Institute of Technology,Harbin 150001 China)

机构地区：[1]哈尔滨工业大学电气工程系,哈尔滨150001

出　　处：《电工技术学报》2023年第20期5488-5502,共15页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51922033);台达电力电子科教发展计划(DREK2020003)资助项目。

摘　　要：随着新型可再生能源的快速发展,对高效、高升压比DC-DC变换器的需求日益增加。传统两级级联式结构中,前后两级均需传递全部功率,不利于系统效率的提升。为此,该文提出一种基于输入并联输出串联(IPOS)连接的上下堆叠式高升压比直流变换器,系统的上部分变换器工作在直流变压器(DCX)状态,实现恒电压比传输,处理大部分功率,通过对谐振点处的参数优化实现效率提升;下部分变换器则起到系统闭环动态调压的作用,传输小部分功率。该文详细介绍所提出结构的工作原理、参数设计以及平面变压器的优化设计,并搭建24~32 V/400 V、额定功率200 W、开关频率1 MHz的实验样机验证了理论分析的正确性,所搭建样机峰值测试效率高达96.3%。Nowadays,with the rapid depletion of traditional fossil fuels,the harm to the environment is becoming more prominent.The proliferation of renewable energy resources has solved the energy shortage problem and realized sustainable development.The high step-up DC-DC converters have received widespread attention in renewable energy systems,such as photovoltaic module-integrated converters,fuel cells,and hybrid electric vehicles.In general,the high step-up DC-DC converters can be divided into non-insolated and isolated types.The non-isolated DC-DC converters usually adopt coupled inductors and voltage multiplier cells to realize the boost capability.In contrast,the isolated structures can realize the galvanic isolation and the expected voltage gain by changing the transformer turns ratio,which is more suitable for high step-up applications with high safety performance.The LLC resonant converter has gained popularity due to the soft switching properties of power devices,constant conversion ratio,and high working efficiency near the resonant working point.However,it will generate large current stress on the primary side of the transformer when a high boost ratio is achieved,causing additional ESR losses of the resonant components and efficiency sacrifice.Thus,the resonant tank is usually located at the secondary side in high step-up applications,and the system voltage gain of LLC is regulated by pulse frequency modulation.The switching frequency change will make the resonant point deviate from the ideal state and generate additional reactive power,which brings difficulties to the design of EMI filters and magnetic components.Besides,the soft switching range of power devices is affected as the switching frequency changes.Although LLC is preferable to operate in the unregulated state,it will lose the voltage regulation capacity.Therefore,the two-stage architecture is a popular solution,where LLC can perform as a DC transformer(DCX),and the system dynamic regulation is achieved by the front or latter DC-DC stage.However,a

关 键 词：输入并联输出串联(IPOS) 直流变压器(DCX) 高升压 高频 高效 

分 类 号：TM46[电气工程—电器]