利用单端电流的高压直流输电线路全线速动保护  

A New Whole-line Quick-action Protection Principle for HVDC Transmission Lines Using One-end Current

作　　者：高淑萍[1] 索南加乐[1] 宋国兵[1] 蔡新雷[1] 

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049

出　　处：《中国电机工程学报》2012年第7期107-113,198,共7页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51177128;51037005);Project Supported by National Natural Science Foundation of China(51177128;51037005)

摘　　要：针对传统直流输电线路单端量保护可靠性差、灵敏度不足的问题,提出一种仅利用单端电流实现直流输电线路全线速动的保护原理。通过对换流站的平波电抗器和直流滤波器所构成电网络的阻抗特性分析发现,对于特定频带而言,区内、外故障时它们所表现出的阻抗特性差异巨大,进而得出区内、外故障时特定频带电流差异显著。该方法对采样频率的要求低,而且具有绝对的选择性,易于硬件实现,可靠性高,具有较大的工程实用价值,可取代现有的行波保护作为直流输电线路的主保护。仿真结果表明,在各种工况下,该原理都可以实现故障极选择,并能快速、灵敏、可靠地区分区内、外故障。A novel quick-action high voltage direct current （HVDC） transmission line protection principle only using one-end current signals is proposed in order to solve the problems in traditional protection principles, such as poor reliability and insufficient sensitivity. By analyzing the impedance characteristic of the electric network, which is made of reactance and DC-filter of HVDC transmission systems, it is found that the difference of the impedance characteristic in some special frequency-bands is distinct when an intemal or external fault of the DC line that the measured current occurs. Furthermore it is obtained is obviously different for some special frequency-band signals between internal or external faults. Compared with the traditional protection methods, the protection principle is simpler, the sample frequency could be lower, and it is easier to be implemented. It can be the primary protection of HVDC transmission lines instead of the current traveling wave protection. Simulation results show that the proposed protection principle can identify the fault pole and identify between the internal and external faults. It can rapidly operate with high sensitivity and selectivity in different fault conditions.

关 键 词：高压直流输电线路 继电保护 全线速动 单端电流 特定频率带 

分 类 号：TM77[电气工程—电力系统及自动化]