基于电流馈电型开关电容的多重模块化直流变压器及其优化调制策略  

Research on Current-fed Switched-capacitor-based Multiple Modular DC Transformer and Its Optimized Modulation Strategy

作　　者：孙谦浩 李亚楼[2] 孟经伟 赵彪[1] 穆清[2] 张星[2] SUN Qianhao;LI Yalou;MENG Jingwei;ZHAO Biao;MU Qing;ZHANG Xing(Department of Electrical Engineering,Tsinghua University,Beijing 100084,China;China Electric Power Research Institute,Beijing 100192,China)

机构地区：[1]清华大学电机工程与应用电子技术系,北京100084 [2]中国电力科学研究院,北京100192

出　　处：《控制与信息技术》2019年第6期36-42,84,共8页CONTROL AND INFORMATION TECHNOLOGY

基　　金：国家自然科学基金(51877116)

摘　　要：针对中压直流电网中不同中压直流母线的连接问题,文章提出了一种基于电流馈电型开关电容的输入串联输出串联多重模块化直流变压器(current-fed switched-capacitor-based input-series-output-series multiple modular DCtransformer,CFSC-DCT)拓扑结构。相比于传统的基于双主动全桥的多重模块化直流变压器,CFSC-DCT在拓扑上具有关键的在线冗余设计与直流故障隔离功能,从而提高了中压直流电网的运行可靠性;同时,为了优化其高频链环节的电流应力,一种双重高频链电压幅值匹配调制策略被应用于所提出的CFSC-DCT。仿真结果表明,在该调制策略下,CFSC-DCT的高频链电压始终处于匹配状态,避免了传统方波调制下的直流端电压不匹配现象,优化了其高频链电流应力,提高了直流变压器自身及中压直流电网的平均运行效率与经济效益。To solve the connecting issue of different medium-voltage DC(M VDC)buses in MVDC pow er grids,a current-fed switched capacitor-based input-series-output-series multiple modular DC transformer(CFSC-DCT)was designed in this paper.Compared with the traditional dual-active-bridge based DCT,CFSC-DCT has the key online redundant design and DC fault isolation capability from the view of topology,thus improving the reliability of MVDC power grid.Meanwhile,to optimize the current stress in high frequency link(HFL)of CFSC-DCT,a dual HFL voltage amplitudes matching modulation strategy(DAM)is employed for the proposed CFSC-DCT.Based on DAM,the HFL voltages of CFSC-DCT is always under the matching state and the HFL current stress can be optimized,solving the issue of DC terminal voltages mismatch caused by the traditional square-wave modulation,and improving the efficiency and economic benefit of DC transformer and MVDC power grid.

关 键 词：中压直流配电网 直流变压器 电流馈电型开关电容 双重高频链电压幅值匹配调制 高频链电流应力 

分 类 号：U231.6[交通运输工程—道路与铁道工程] TP319[自动化与计算机技术—计算机软件与理论]