基于模量Hausdorff距离波形比较的直流输电线路选择性快速保护方案  

A High-speed Protection Scheme for HVDC Transmission Line Based on Hausdorff Distance Comparison

作　　者：赵航[1] 林湘宁[1] 喻锟[1] 李浩[1] 陈乐[1] 李正天[1] 吴通华 郭志全 

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学),湖北省武汉市430074 [2]南京南瑞集团公司,江苏省南京市210000

出　　处：《中国电机工程学报》2017年第23期6888-6900,共13页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51577077;51477090);国家电网公司科技项目(SGTYHT/16-JS-198)~~

摘　　要：现有的直流输电线路行波保护存在保护死区,而纵联差动保护由于无法躲避暂态电流的影响,只能作为后备保护。文章推导直流输电系统不同位置故障时的整流、逆变侧线模电压行波间的相似性关系:区外故障时两侧波形相似度很高,区内故障时两侧波形存在较大差异性;进而提出一种波形比较的直流输电线路选择性快速主保护方案,该方案引入扫描的方法将两侧的波形进行对齐,进而比较他们之间的相关性,以Hausdorff距离作为保护判据,可以消除暂态时分布电容电流的影响。基于PSCAD模型的仿真结果表明:该文方案可靠性高、速动性好、选极准确、对线路两端通信对时精度要求低、耐过渡电阻性能强,且具有抗采样数据异常和噪声干扰的能力,针对部分死区故障,在可能的情况下闭锁行波保护,实现保护的可靠不误动。Existing high voltage direct current transmission line traveling-wave protection has dead zone, and longitudinal differential protection serves as backup protection because it cannot avoid distributed capacitive current. The similarity between aerial mode voltage traveling wave at rectifier side and inverter side was derived in this paper： there is a great discrepancy between the waveforms at two side when an internal fault occurs, there is a high similarity when an external fault occurs. Therefore, a high-speed primary protection scheme for HVDC transmission line based on Hausdorff distance comparison was proposed, which introduced scanning method to align the waveforms at two sides, then their correlation was analyzed~ and Hausdorff distance was used as the protection criteria, this scheme can eliminate the influence of distributed capacitive current. Finally, a model was constructed on PSCAD to verify the proposed protection scheme, and the simulation results shows that this protection is of high reliability. Besides, it has a low requirement for time precision, an outstanding ability to resist the transmission resistance grounding, noise and abnormal data. In some scenarios when a fault occurs at the dead zone of the lines, the proposed protection can lock the existing traveling wave protection, preventing it from malfunctioning.

关 键 词：高压直流输电线路 相关性分析:Hausdorff距离 分布电容电流 闭锁 

分 类 号：TM77[电气工程—电力系统及自动化]