摘要
风电场集电线上风机众多,故障定位困难,为此提出一种基于负序电流移置的风电场集电线不对称故障定位方案。首先,从风机故障电流出发,分析风机负序阻抗特性,实现风机负序建模,进而在对风电场负序网络等效的基础上引入移置策略。然后,分析电流移置域边界节点负序注入电流的数值特征与故障位置间的关联关系,构造故障区域识别准则,推导故障子区域辨识公式与故障测距公式。最后,探究节点负序注入电流相位特征,提出无须相量测量的节点负序注入电流有效值计算方法。PSCAD/EMTDC仿真表明,所提方案能够克服过渡电阻、故障初相角、风速分布及风机容量等因素影响,有效实现集电线不对称故障精确定位,且所需测点少,无相量测量,含分支集电线适用性好。
A large number of wind turbines are connected through collecting lines in wind farms,which makes the fault localization of collecting lines difficult.Therefore,a negative-sequence current shifting based fault localization scheme for asymmetric faults of collecting lines is proposed in this paper.First,the negative-sequence impedance characteristic of wind turbines(WTs)is analyzed from WT fault current,and the negative-sequence modeling of WTs is realized;thus,a shifting strategy can be introduced after the equivalence of negative-sequence networks of wind farms.Then,correlation between fault locations and numerical characteristics of the negative-sequence injection current(NSIC)at boundary nodes of the current shifting domain is analyzed.On this basis,the identification criterion for faulty domains can be constructed,and the identification formula for faulty sub-domains and the calculation formula for fault distance can be derived.Finally,phase characteristics of NSIC are explored,based on which an RMS calculation method for NSIC is presented without phasor measurement required.Verification by PSCAD/EMTDC shows that this proposed scheme is not affected by factors such as fault resistance,fault inception angles,wind speed distribution and wind turbine capacities.It can effectively achieve the fault localization for asymmetric faults of collecting lines.Besides,the required measurement point is very limited,and phasor measurement is not necessary.It is also applicable to collecting lines with line branches.
作者
丁嘉
朱永利
魏源
DING Jia;ZHU Yongli;WEI Yuan(School of Electrical and Electronic Engineering,North China Electric Power University,Baoding 071003,Hebei Province,China)
出处
《中国电机工程学报》
北大核心
2025年第4期1436-1449,I0017,共15页
PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING
基金
国家自然科学基金(面上基金项目)(51677072)。
关键词
负序网络
负序电流
电流移置
风电场
集电线
不对称故障
故障定位
negative-sequence network
negativesequence current
current shifting
wind farm
collecting line
asymmetric fault
fault localization
