摘要
对直流配电系统线路的保护是直流配电系统安全稳定运行的保障。本文以四端直流配电系统为研究对象,提出一种基于限流电抗电压特性的单端量保护方案。首先,对四端直流配电网的直流线路故障特性进行分析,给出一种限流电抗电压的计算方法。然后,将故障后一段时间内限流电抗电压的变化率及幅值的大小用于判断区内、外故障;以正、负极限流电抗电压的绝对值构成的对数之和作为判据,来实现故障类型的识别和故障选极。最后,在PSCAD/EMTDC中建立四端柔性直流配电网仿真模型,仿真分析表明,本文提出的保护方案仅利用单端电气量即可正确实现故障判别和故障选极,同时能够躲避雷击电流的影响,具有良好的抗过渡电阻及噪声的能力。
The protection of lines in a DC distribution system is the guarantee for its safe and stable operation.In this pa⁃per,a four-terminal DC distribution system is taken as the research object,and a single-ended protection scheme based on the characteristics of current-limiting reactance voltage is proposed.The fault characteristics of the DC line in the four-terminal DC distribution network are analyzed,and a calculation method for the current-limiting reactance voltage is given.According to the fault analysis,it can be seen that the changing rate and magnitude of the current-limiting reac⁃tance voltage within a period of time after the fault can be used to judge the internal or external fault.A criterion is con⁃structed by the sum of logarithms of the absolute values of positive-and negative-pole current-limiting reactance voltag⁃es,which can realize the identification of fault types as well as fault pole selection.A simulation model of a four-termi⁃nal flexible DC distribution network is established in PSCAD/EMTDC,and simulation analysis shows that the proposed protection scheme can identify fault types and select fault poles by only using single-ended electrical quantities.At the same time,it can avoid the impact of lightning current,with a satisfying capability to resist the transition resistance and noise.
作者
季路
汤亚芳
袁旭峰
张孝荟
李雨龙
JI Lu;TANG Yafang;YUAN Xufeng;ZHANG Xiaohui;LI Yulong(School of Electrical Engineering,Guizhou University,Guiyang 550025,China)
出处
《电力系统及其自动化学报》
CSCD
北大核心
2022年第10期15-23,41,共10页
Proceedings of the CSU-EPSA
基金
国家自然科学基金资助项目(52067004)。
关键词
直流配电系统
限流电抗电压
故障识别
故障选极
DC distribution system
current-limiting reactance voltage
fault identification
fault pole selection
作者简介
季路(1996-),男,硕士研究生,研究方向为电力系统继电保护。Email:1426035519@qq.com;通信作者:汤亚芳(1976-),女,硕士,副教授,研究方向为电力系统继电保护。Email:1560368@qq.com;袁旭峰(1976-),男,博士,教授,研究方向为电力电子在电力系统中的应用、电力系统运行与控制。Email:17015606@qq.com。
