基于高频阻抗突变量的双馈风场送出线路保护方法  

Protection Method for Doubly Fed Wind Farm Transmission Lines Based on High Frequency Impedance Sudden Variables

作　　者：马静 张宇锋 徐国杰 MA Jing;ZHANG Yufeng;XU Guojie(State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Beijing 102206,China)

机构地区：[1]新能源电力系统全国重点实验室(华北电力大学),北京102206

出　　处：《高电压技术》2024年第6期2663-2672,I0016,I0017,共12页High Voltage Engineering

基　　金：国家重点研发计划(2021YFB1600202)。

摘　　要：针对双馈风机的暂态特性呈现多态性且区别于传统同步机,双馈风机的短路电流频率含有比例较大的衰减转速频率分量导致送出线路区内外故障难以区分,传统保护容易出现误动拒动的现象,提出了一种基于高频阻抗突变量的双馈风场送出线路纵联保护方法。首先,结合双馈风电场拓扑结构,考虑集电线上各风机机端电压幅值相角差异,求得双馈风场短路电流,提取高频分量并构造双馈风电场故障高频模型。在此基础上,构建双馈风场送出线路高频突变量网络,并推导送出线路两侧保护所测得的高频阻抗,利用高频突变量网络区内外测得阻抗差异性,构造保护判据。最后,利用RT-LAB平台进行仿真,验证了所提方法可实现区内外故障的准确判别,且无需线路两端信息实时同步。The transient characteristics of the doubly-fed fan are polymorphic and different from the traditional synchronous machine,and the short circuit current frequency of the doubly-fed fan contains a large proportion of the decaying speed frequency component,which makes it difficult to distinguish the faults inside and outside the transmission line area,meanwhile,the traditional protection is prone to mis-operation and non-operation;therefore,a pilot protection method for outgoing line of DFIG wind farm based on high-frequency impedance sudden variable is proposed.First,combined with the topology of the doubly-fed wind farm,the difference of the voltage amplitude and phase angle of the fan terminals on the collector line is taken into account,the short-circuit current of the doubly-fed wind farm is obtained,and the high-frequency component is extracted to construct the fault high-frequency model of the doubly-fed wind farm.On this basis,the high-frequency sudden variable network of the transmission line of the doubly-fed wind farm is constructed,and the high-frequency impedance measured by the protection on both sides of the transmission line is derived,and the protection criterion is constructed by using the impedance difference measured inside and outside the high-frequency sudden variable network area.Finally,the RT-LAB platform is used to simulate and verify that the proposed method can accurately identify the faults in and out of the zone and that real-time synchronization of information is not required at both ends of the line.

关 键 词：双馈风电 送出线路 纵联保护 故障高频模型 高频阻抗突变量 

分 类 号：TM614[电气工程—电力系统及自动化] TM773