环状有源配电网改进电流差动保护方案  

An improved current differential protection scheme for annular active distribution networks

作　　者：刘科研 叶学顺 李昭 魏来 李波[2] LIU Keyan;YE Xueshun;LI Zhao;WEI Lai;LI Bo(China Electric Power Research Institute,Beijing 100192,China;School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]中国电力科学研究院有限公司,北京100192 [2]西南交通大学电气工程学院,四川成都610031

出　　处：《电力科学与技术学报》2023年第3期157-165,共9页Journal of Electric Power Science And Technology

基　　金：国家电网公司总部科技项目(5400-202099524A-0-0-00)。

摘　　要：为提高配电网供电可靠性和分布式电源接纳能力,有源环状网络成为配电网主要发展方向之一。然而,大量分布式电源接入改变了配电网潮流和故障特征,传统三段式电流保护方案可靠性不足。为此,提出一种针对环状有源配电网的改进电流差动保护方案。首先对环状有源配电网区内、外故障电流关系表达式进行推导,分析两端电流故障分量的向量关系;然后利用保护区段两端故障电流比构造主保护判据,进一步地针对环状结构配电网设置避免保护误动的辅助判据;最后利用PSCAD/EMTDC仿真平台搭建环状有源配电网模型,通过大量仿真分析,验证所提保护方案的有效性和抗干扰能力。该方案同样适用于典型辐射状有源配电网。In order to improve the power supply reliability and the source acceptance capacity of distribution networks,the active ring network has become one main development trend of the distribution network.However,the connection of numerous distributed power sources will impact the power flow and fault characteristics,and thus reduce the performance of the traditional three⁃stage current protection scheme.In this regard,an improved current differential protection scheme is proposed for annular active distribution networks in this paper.Firstly,the expressions for the relationship between the fault currents inside and outside the annular active distribution network are derived,and thus the vectorial relationship between the fault current components at both ends can be figured out.Then the main protection criterion is constructed by the fault current ratio of the two ends of protected area section.,and the auxiliary protection criterion to avoid protection misoperation is also set for the annular structure distribution network.Finally,the PSCAD/EMTDC simulation platform is used to verify the effectiveness and interference resistance of the proposed protection scheme.

关 键 词：电流差动保护 环状有源配电网 电流故障分量 分布式电源 

分 类 号：TM77[电气工程—电力系统及自动化]