柔性直流配电网故障分析

2018年4月电工技术学报Vol.33 No. 8 第33卷第8期TRANSACTIONS OF CHINA ELECTROTECHNICAL SOCIETY Apr. 2018

DOI: 10.19595/https://www.360docs.net/doc/ca13434453.html,ki.1000-6753.tces.161814

柔性直流配电网故障分析

戴志辉1葛红波1严思齐1王增平1陈曦2

（1. 分布式储能与微网河北省重点实验室（华北电力大学）保定 071003

2. 国网保定供电公司发展策划部保定 071000）

摘要柔性直流配电网故障特性分析是保护方案设计的基础。当前，直流系统故障期间，换流器IGBT不闭锁时的故障特性尚未深入探讨。首先，确定直流配电网的接地方式和控制策略。

其次，分析IGBT不闭锁时直流极间短路和单极接地短路的故障特性及过渡电阻等因素的影响，

并讨论故障对其他区域的影响。结果表明，对于极间短路，除故障达到稳态后IGBT闭锁较之不

闭锁会出现极间电压和故障电流增大的现象外，IGBT闭锁与否对故障特性影响不大；对于单极

接地短路，IGBT不闭锁会使直流侧出现不平衡电压，导致换流器交流侧电流出现直流分量。最

后，在PSCAD/EMTDC中搭建仿真模型，证明了理论分析的正确性。

关键词：直流配电网接地方式故障分析极间故障单极故障

中图分类号：TM77

Fault Analysis of Flxible DC Distribution System

Dai Zhihui1 Ge Hongbo1 Yan Siqi1 Wang Zengping1Chen Xi2

（1. Key Laboratory of Distributed Energy Storage and Microgrid of Hebei Province

North China Electric Power University Baoding 071003 China

2. Development and Plan Department Baoding Power Supply Company of

State Grid Corporation of China Baoding 071000 China）

Abstract The fault analysis of flexible DC distribution grids is the basis of designing the protection scheme. Up to now, the fault characteristic of DC fault, considering unblocked IGBT in converters, has not been systematically investigated. Firstly, the grounding mode and the control strategy of the DC distribution grid were determined. Secondly, on the premise that IGBT is unblocked, this paper analyzed fault characteristics of pole-to-pole fault and pole-to-ground fault, as well as the influence of fault resistance. The impacts of DC faults on other sections were also discussed. The results show that, with regard to the pole-to-pole fault, whether IGBT is blocked or not does not affect the fault characteristic evidently in the first two transient stages. However, when the fault reaches the steady state, compared with the condition that the IGBT is unblocked, the DC voltage and fault current are larger when the IGBT is blocked. In terms of the pole-to-ground fault, the unblocked IGBT would result in DC unbalance voltage, which will further generate DC components in the ac-side current of the converter. Finally, the simulation model was built in PSCAD/EMTDC, and the result confirms the validity of the theoretical analysis.

Keywords：DC distribution network, grounding mode, fault analysis, pole-to-pole fault, pole- to-ground fault

国家重点研发计划专项课题（2016YFB0900203）、国家自然科学基金（51307059）和中央高校基本科研业务费（2017MS096）资助项目。收稿日期 2016-11-18 改稿日期 2017-02-26

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