不依赖边界元件及同步对时的多端柔直电网波形匹配式差动保护原理  

Waveform Matching Based Protection Strategy for VSC-MTDC Independent on Synchronization and Boundary Component

作　　者：童宁[1] 范理想 林湘宁[1] 随权 金能[1] 陈乐[1] 马啸 李正天[1] TONG Ning;FAN Lixiang;LIN Xiangning;SUI Quan;JIN Neng;CHEN Le;MA Xiao;LI Zhengtian(State Key Laboratory of Advanced Electromagnetic Engineering and Technology (Huazhong University of Science andTechnology),Wuhan 430074,Hubei Province,China)

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)

出　　处：《中国电机工程学报》2019年第13期3820-3832,共13页Proceedings of the CSEE

基　　金：国家电网公司科技项目(5100-201999331A-0-0-00);中国博士后科学基金项目(2018M642838)~~

摘　　要：多端柔直电网发生线路故障时,目前常用应对策略缺乏选择性,容易发生重合于永久性故障、全网停运等问题,而现有研究尚未验证边界保护在"网孔结构"工程中的适应性,差动类保护缺乏对同步误差及异常采样数据的应对能力。为解决上述问题,该文首先分析了多端柔直电网线路故障场景下的行波复杂折反射现象,揭示故障线路与非故障线路两侧同名行波与异名行波首波头的衰减特性差异,进而利用Hausdorff距离表征并度量上述差异;结合突变量启动判据,形成一套不依赖同步对时及边界元件的波形匹配式差动保护。仿真结果表明,所提出的保护原理具有良好的速动性及选择性,且在采样数据中包含大量异常数据时依然具有良好的动作性能。Conventional methodologies are lack of selectivity coping with the line fault for VSC-MTDC, as the whole system should be blocked if re-start under permanent fault conditions. However, the validations of boundary protection are not proved in the meshed structure projects, and the differential protection methods are lack of capability against synchronization error and abnormal data. To solve this, this paper firstly analyzed the complex refraction and reflection phenomenon in the VSC-MTDC, and the attenuation difference between the homonymic traveling waves and anonymous traveling waves were analyzed. Based on the Hausdorff algorithms, the above differences were expressed. A novel protection scheme independent on boundary component and synchronization was proposed using Hausdorff distance differential protection and the superimposed component energy start?up criterion. By means of simulation analysis, the proposed protection scheme works well under different fault conditions, and has good selectivity and speed even the sampling data is with a great amount of error.

关 键 词：差动保护 多端柔直电网 边界元件 采样异常 

分 类 号：TMD1[电气工程]