摘要
为分析固有频率差动保护在线路上盲点的分布,解决固有频率差动保护在盲点故障时存在的问题,提高保护动作的可靠性和快速性,提出一种基于电流行波固有频率的输电线路纵联保护方法。通过分析输电线路故障时的电流频谱特征,用多信号分类(multiple signal classification,MUSIC)算法得到固有频率后,利用线路两端固有频率主频差构成保护主判据来判断区内、外故障。针对频差保护区内盲点问题,分析了不同系统阻抗下的盲点分布,在此基础上,利用固有频率的二次成分在区内盲点和区外故障时的显著差异构成辅助判据,以区分区内盲点故障与区外故障。该方法仅利用了电流信息,性能可靠,动作灵敏,适应性强。PSCAD/EMTDC仿真和Matlab分析验证了该方法的有效性。
To analyze the distribution of blind spot for differential protection based on natural frequency, solve the protection problems of internal fault at blind spot and improve the protection reliability and rapidity, a pilot protection for transmission lines based on natural frequencies of current was proposed. The spectrum characteristic of fault currents was analyzed and the natural frequencies were extracted by multiple signal classification algorithm. The difference between the dominant natural frequencies at two ends of a transmission line was used as the primary criterion to discriminate the internal faults and external faults. For the blind zone issue of the primary criterion, the distribution of the blind spot was analyzed under different system impedances. On this basis, the distinct difference of the secondary natural frequency under the internal faults and external faults was utilized as the secondary criterion to discriminate the internal faults at blind spot and the external faults. The proposed method only uses the current and possesses reliable performance, sensitive operation and strong adaptation. The simulation results in PSCAD/EMTDC and Matlab analysis validate the effectiveness of the proposed method.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第28期121-129,19,共9页
Proceedings of the CSEE
基金
国家高技术研究发展计划项目(863项目)(2012AA050208)~~
关键词
输电线路
纵联保护
固有频率
保护盲点
系统阻抗
transmission lines
pilot protection
natural frequency
protection blind spot
system impedance
