中国电力 ›› 2018, Vol. 51 ›› Issue (10): 56-63.DOI: 10.11930/j.issn.1004-9649.201702043

• 电网 • 上一篇    下一篇

非隔离双向四端口直流变换器及其控制策略研究

崔红芬, 姚良忠, 桑丙玉, 杨波, 陶以彬   

  1. 中国电力科学研究院有限公司, 江苏 南京 210003
  • 收稿日期:2017-02-14 修回日期:2018-04-03 出版日期:2018-10-05 发布日期:2018-10-12
  • 作者简介:崔红芬(1984-),女,工程师,从事柔性直流输电技术、分布式新能源并网技术研究,E-mail:cuihongfen@epri.sgcc.com.cn;姚良忠(1961-),男,高级工程师(教授级),博士生导师,从事电力系统分析及大型风电场并网技术研究,E-mail:yaoliangzhong@epri.sgcc.com.cn;桑丙玉(1983-),女,工程师,从事分布式发电与微网、储能优化配置与控制研究,E-mail:sangbingyu@epri.sgcc.com.cn;杨波(1977-),男,硕士,高级工程师,从事电力系统储能应用、新能源发电技术研究,E-mail:yangbo@epri.sgcc.com.cn;陶以彬(1977-),男,高级工程师,从事现代电力电子技术、微电网技术及电力储能技术研究,E-mail:taoyibin@epri.sgcc.com.cn
  • 基金资助:
    国家电网公司科技项目(新能源发电基地多电压等级直流汇集网及运行控制技术研究,NY71-16-044)。

Research on Non-Isolated Bidirectional Four-Port DC-DC Converter and Its Control Strategy

CUI Hongfen, YAO Liangzhong, SANG Bingyu, YANG Bo, TAO Yibin   

  1. China Electric Power Research Institute, Nanjing 210003, China
  • Received:2017-02-14 Revised:2018-04-03 Online:2018-10-05 Published:2018-10-12
  • Supported by:
    This work is supported by Science and Technology Project of State Grid Corporation of China (Research on Multi-Voltage Level DC Collection Network and Operation Control Technology of Renewable Energy Generation Base, No.NY71-16-044).

摘要: 针对多端直流输电系统中的潮流汇集、分配以及电压变换需求,提出了一种基于双向buck+boost变换器的非隔离双向四端口直流变换器。所提出的直流变换器只需经过DC-DC单级升降压变换,提高了变换器的效率和功率密度;相对于传统多端口变换器通过公共交流母线或公共直流母线连接的方案,该变换器无需采用母线电容和交流变压器,降低了变换器体积和成本,提高了系统可靠性;该变换器中任意一个输入到输出端口之间均构成一个双向buck+boost变换器单元,各个单元在功率回路不存在相互耦合,控制更易实现。在PSCAD/EMTDC平台中搭建了四端双极柔性直流输电系统仿真模型,对直流变换器潮流分配和电压变换功能进行了仿真分析,并研制了双极四端口直流变换器原理样机,进行了相应的动模实验验证。仿真和动模实验结果表明,该直流变换器能够有效实现直流潮流分配和电压变换功能。

关键词: 潮流分配, 直流变换器, 双极直流电网, 柔性直流输电, 双向buck+boost变换器

Abstract: The paper proposes a non-isolated four-port bidirectional DC converter based on bidirectional buck-boost converter, to accommodate the needs of power flow confluence, distribution and voltage conversion. The proposed DC converter enhances the efficiency and power density by achieving voltage step-up through a single process. Compared with the conventional practice where multi-port converters are connected with a common AC or DC bus, the proposed design sees reduction in both volume and costs and improvement in reliability by eliminating the DC capacitor and AC transformer. In the converter, any selected pair of input and output ports can be considered as a buck-boost unit, there is no coupling among different units in terms of power circuits. Therefore, it is easy to be realized. After analyzing the operational mechanism of the proposed DC converter, a four-terminal bipolar DC transmission system is established in PSCAD/EMTDC, to demonstrate and validate the effectiveness of the proposed DC converter. An example device is also developed for the purpose of further validation. Simulation results suggest that the proposed DC converter can perform the task of power flow distribution and voltage step-up.

Key words: power flow regulation, DC-DC converter, bipolar DC grid, flexible HVDC, bidirectional buck-boost converter

中图分类号: