特高压直流输电线路雷击暂态过程与行波保护响应特性分析  

Thunderstruck Transient Process of UHVDC Transmission Line and Response Characteristic of Traveling Wave Protection

作　　者：李书勇[1] 郭琦[1] 崔柳[1] 蔡泽祥[2] 梁益[2] 

机构地区：[1]中国南方电网科学研究院有限责任公司,广东省广州市510080 [2]华南理工大学电力学院,广东省广州市510640

出　　处：《电网技术》2015年第10期2830-2835,共6页Power System Technology

摘　　要：针对实际工程中特高压直流输电线路雷击事件,采用电磁暂态仿真软件PSCAD/EMTDC实现雷击特高压线路的小步长仿真,解决了目前仿真方法未能与保护分析工作相适应的问题。主要分析了发生非故障性绕击、故障性绕击以及反击时保护安装处电压、电流的暂态过程,描述各电气暂态量在雷击极与非雷击极的主要特征及区别。结合实际行波保护模型的动作情况,对比非故障性绕击、故障性绕击以及反击下d U/dt判据、DU判据、DI判据在雷击极与非雷击极的响应结果,梳理雷击特高压直流输电线路行波保护判据的响应特性,指出在故障性绕击、反击场景下非雷击极行波保护误动情况是由于线路耦合导致在雷电流波头上升阶段出现非雷击极保护的DU、DI判据满足整定值造成的。最后给出了提高特高压直流系统行波保护雷击可靠性的优化思路。For contingency of lightning stricken UHVDC transmission lines, small-step simulation of lightning stricken UHVDC transmission lines based on EMTDC is fulfilled, and problem of current simulation approach not adaptable to protection analysis is solved. This paper analyzes transient process of voltage and current at relay location when non-fault shielding failure, fault shielding failure and back flashover occurs, and characterizes main features of electrical transient variables of lightning stricken and non-lightning stricken poles. Comparing response of dU/dt criterion with zXU and A/ criteria of non-fault shielding failure, fault shielding failure and back flashover at stricken and non-stricken poles, the paper summarizes response characteristic of UHVDC transmission traveling wave protection criteria according to actions of traveling wave protection, and finds out that under situation of fault shielding failure and back flashover, incorrect action of traveling wave protection at non-lightning stricken pole is caused by coupling between lines, making AU and A/criteria satisfied at lightning current wave front. Finally, an optimization idea of improving reliability of protection system is put forward as reference for engineering application.

关 键 词：特高压直流系统 雷击暂态过程 行波保护 响应特征 

分 类 号：TM77[电气工程—电力系统及自动化]