电网技术2024，Vol.48Issue(5)：2170-2178,中插71-中插73,12.DOI:10.13335/j.1000-3673.pst.2023.0509
混合级联特高压直流输电线路纵联差动保护适应性分析
Adaptability Analysis of Pilot Differential Protection for Hybrid Cascaded UHVDC Transmission Lines
摘要
Abstract
To explore the adaptability of the existing pilot differential protection for the dc lines to the hybrid cascaded ultra-high-voltage direct current(UHVDC)transmission system,combined with the operation modes of this system,the fault characteristics and protection adaptability of the dc system faults at different locations under three special operating modes are analyzed by theoretical analysis and simulation.The theoretical analysis shows that the pilot differential protection is good in adaptability.The simulation analysis shows that the DC line distribution capacitance and the modular multilevel converter(MMC)control characteristics of the inverter side may cause the dc line current delayed self-decrement to fluctuate for a long time during a DC line fault,resulting in a very long lockout duration of the pilot differential protection.Currently,the system suffers the super fault current impact of the MMC for a long time.When there is a failure outside the DC line area,the DC current difference between the rectifier side and the inverter side may have a large absolute value and be in a fluctuating state for a long time,existing a risk of incorrect operations in the pilot differential protection.关键词
混合级联特高压直流输电系统/纵联差动保护/适应性分析/运行方式/保护误动Key words
hybrid cascade UHVDC transmission system/pilot differential protection/adaptability analysis/operation mode/protection mis-operation分类
信息技术与安全科学引用本文复制引用
牟大林,林圣,李小鹏..混合级联特高压直流输电线路纵联差动保护适应性分析[J].电网技术,2024,48(5):2170-2178,中插71-中插73,12.基金项目
国家自然科学基金项目(51977183).Project Supported by National Natural Science Foundation of China(NSFC)(51977183). （51977183）
