中国电机工程学报2025，Vol.45Issue(11)：4244-4255,12.DOI:10.13334/j.0258-8013.pcsee.232596
基于运算阻抗离散域模型的柔直电网线路纵联保护
A Novel Pilot Protection for Flexible DC Grid Line Based on Discrete Domain Model of Operational Impedance
摘要
Abstract
Flexible DC grid is an effective solution to address the challenge of large-scale new energy transmission.However,the existing protection methods for flexible DC grid lines are unable to fundamentally eliminate the impact of fault resistance.Therefore,a novel pilot protection for flexible DC grid line based on a discrete domain model of operational impedance is proposed.First,the operational impedance characteristic differences are analyzed under internal and external faults.Then,the operational impedance is considered as the transfer function in the s-domain.The bilinear transformation is employed to convert it into a z-domain function,and the discrete domain model of operational impedance that can be calculated with the sampling sequence is obtained.Subsequently,considering the interference in the field,the sampling sequences are reconstructed through accumulation point by point.A sequence matching algorithm is employed to establish directional criteria and develop a comprehensive protection scheme.Finally,simulation tests are conducted to validate the proposed scheme,demonstrating its ability to quickly and reliably identify line faults.The proposed protection is capable of withstanding fault resistance up to 1 000 Ω,without the need for threshold setting,characteristic frequency-band extraction,or strict synchronization of dual-end data.关键词
柔性直流电网/纵联保护/行波/双线性变换/采样序列重构/序列匹配Key words
flexible DC grid/pilot protection/traveling wave/bilinear transformation/sampling sequence reconstruction/sequence matching分类
信息技术与安全科学引用本文复制引用
戴志辉,石旭..基于运算阻抗离散域模型的柔直电网线路纵联保护[J].中国电机工程学报,2025,45(11):4244-4255,12.基金项目
国家自然科学基金项目(51877084).Project Supported by National Natural Science Foundation of China(51877084). （51877084）
