张勇;夏杨红;朱洁;赵贺;于淼;韦巍;

• 1:浙江大学电气工程学院
• 2:国网北京电力科学研究院

摘要(Abstract)：

直流微网中的分布式发电单元(DG)将可再生能源转化为电能,并通过并联H桥DC/DC变流器将电能输送到直流母线,能够有效地解决能源危机和环境污染问题。但由于很多DG安装在室外,线路易于老化使绝缘变差,特别在雷雨天气时,DG侧容易发生接地故障,导致某些变流器内部流过很大的共地环流,这会触动变流器过流保护装置从而影响系统稳定性。针对直流微网中多DG负极接地故障造成的共地环流问题,利用双自由度控制策略对共地环流进行抑制,从而有效地提高系统的故障穿越能力,并且系统在正常运行和故障情况下无需控制策略切换,从而不影响经济成本。首先论证传统双极性调制方法不能抑制所述共地环流,然后提出双自由度控制策略,即通过共模控制来抑制共地环流,并且通过下垂控制来提高各变流器均流精度,同时施加惯性环节抑制电压跌落,最后通过仿真和实验结果表明各种工况下所提控制方法的优越性。

关键词(KeyWords)： 分布式发电单元;并联H桥DC/DC变流器;接地故障;共地环流;共模控制

Abstract:

Keywords:

基金项目(Foundation): 国家重点研发计划项目(2016YFB0900500);; 国家电网科技计划项目(SGBJDK00DWJS1700158);; 浙江省重点研发计划(2017C01039)~~

作者(Author): 张勇;夏杨红;朱洁;赵贺;于淼;韦巍;

Email:

DOI: 10.13335/j.1000-3673.pst.2018.0241

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