摘要
当分布式电源采用小电阻接地方式接入配电网时,流过各线路的零序电流的幅值和相位关系发生了变化,传统的保护方法可能失效。针对含分布式电源的小电阻接地有源配电网,提出了一种基于余弦相似度的单相接地故障保护方案。对于相邻中性点之间的线路,采取基于两端零序电流之间的余弦相似度的纵联保护方法;对于不含分布式电源的线路以及分布式电源并网点的下游线路,采取基于线路出口处与相邻中性点处的零序电流之间的余弦相似度的保护方法。该方案的耐过渡电阻能力接近3000Ω,在发生电弧接地故障时同样适用,提高了含分布式电源线路的供电可靠性。最后,通过接地故障仿真验证了所提方案的有效性。
When distributed generation are connected to the distribution network through low resistance grounding,the amplitude and phase relationship of the zero sequence current flowing through each line change,and traditional protection methods may fail.This paper proposes a single-phase grounding fault protection scheme based on cosine similarity for low resistance grounded active distribution networks containing distributed generations.For the lines between adjacent neutral points,a pilot protection method based on the cosine similarity between the zero sequence currents at both ends is adopted.For lines without distributed generations and downstream lines with distributed power grid connection points,a protection method based on the cosine similarity between the zero sequence current at the line outlet and adjacent neutral points is adopted.The fault resistance capability of this scheme can reach 3000Ω,which is also applicable in the event of arc grounding faults,improving the power supply reliability of lines with distributed generations.Finally,the effectiveness of the proposed scheme was demonstrated through grounding fault simulation.
作者
甘锴
陈益哲
高宜凡
王刚
GAN Kai;CHEN Yizhe;GAO Yifan;WANG Gang(Zhaoqing Power Supply Bureau,Guangdong Power Grid Co.,Ltd.,Zhaoqing 526000,China;Shandong Kehui Power Automation Co.,Ltd.,Zibo 255087,China)
出处
《供用电》
北大核心
2025年第9期55-64,共10页
Distribution & Utilization
基金
中国南方电网有限责任公司科技项目[031200KK52222025(GDKJXM20222218)]。
关键词
分布式电源
小电阻接地
有源配电网
单相接地故障
余弦相似度
接地保护
distributed generation
low resistance ground
active distribution network
single phase grounding fault
cosine similarity
grounding fault protection
