中文摘要：

随着世界范围内大力发展直流电网,作为直流电网中关键器件之一的高压大容量DC/DC变换器的研究尤为重要。针对目前关于DC/DC变换器研究主要集中于中低压小功率场合的现状,该文首先从多个角度对直流电网用的高压大容量DC/DC变换器进行了需求分析;其次,对现有文献中提出的适用于直流电网的DC/DC变换器拓扑进行了研究,并将输入端串联输出端串联(input-series output-series,ISOS)结构和低压DC/DC变换器相结合,提出了用于直流电网中输入端和输出端均为高电压场合的ISOS型DC/DC变换器。比较分析了不同拓扑变换器的电压变比、开关器件的电气应力和故障处理能力等,为选择合适的高压大容量DC/DC变换器拓扑提供了依据。

英文摘要：

ABSTRACT:As DC/DC converter is one of the most critical components in DC grids, the study of high voltage and high power DC/DC converter is increasingly important with the rapid development of DC grid all over the world. However, the study of DC/DC converter is mostly focused on low or middle voltage and low power applications. In this paper, the requirements of DC/DC Converters used in large DC grids are addressed firstly. And then possible DC/DC converter topologies are reviewed and input-series and output series DC/DC converter is proposed. Finally, in order to provide a basis for selecting suitable high voltage and high power converters in DC grids, the voltage stresses, voltage conversion ratios and fault management ability of different converters topologies are analyzed.