五端直流电网电压控制及功率分配策略  

DC Voltage Control and Power Dispatch Strategy of a Five-Terminal VSC-Based DC Grid

作　　者：王凯[1] 孙海顺[1] 胡晓波[2] 张珂[1] 

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学),武汉市430074 [2]中国电力科学研究院,北京市100192

出　　处：《电力建设》2015年第4期52-58,共7页Electric Power Construction

基　　金：国家电网公司科技项目(直流电网基础理论研究)

摘　　要：电压源直流电网适用于风力发电场并网及远距离电力输送,为保证直流电网电力传输的灵活性,研究人员提出了多种直流电压控制及功率分配策略。基于对直流电压偏差控制和直流电压下垂控制策略优缺点的分析,提出了一种新的控制策略。该控制策略可提高直流电网稳态运行时的电压精确跟踪能力,并实现主换流站退出运行后直流电网控制模式的平稳转换。基于PSCAD/EMTDC仿真平台,建立了含有1个大型海上风电场和4个陆上交流系统的五端电压源直流电网平均值模型,通过对比风功率波动、主换流站退出运行等不同场景下直流电网的稳态、暂态特性,验证了所提出控制策略的有效性和优势。DC grids based on voltage source converters（ VSCs） have been proposed for integrating large w ind farms and delivering remote energy source pow er through long distance. A number of DC voltage control and pow er dispatch strategies have been presented by researchers to guarantee the pow er transmission＇s flexibility and capacity of such DC grids. Based on the analysis on the advantages and disadvantages of DC voltage margin control strategy and DC voltage droop control strategy,a novel control strategy w as proposed to achieve the goal of both precise DC voltage tracking under normal operation and steady control mode conversion after slack-bus terminal loss. Based on PSCAD / EM TDC simulation platform,a mean value model of a five-terminal VSC-based DC grid w ith four onshore AC systems and one offshore DC system w as built. Through the comparison on the steady-state and dynamic-state characteristics of the DC grid under w ind pow er variation,main converter station tripping and other conditions,the validity and advantages of the proposed control strategy w ere verified.

关 键 词：电压控制 功率分配 偏差控制 下垂控制 主垂控制 

分 类 号：TM721.1[电气工程—电力系统及自动化]