柔性直流输电的改进行波保护仿真研究  

Simulation study of an improved traveling wave protection for VSC-HVDC transmission system

作　　者：张冰[1] 赵书强[1] 甄永赞[1] 

机构地区：[1]华北电力大学电力工程系,河北保定071003

出　　处：《电力系统保护与控制》2017年第16期58-63,共6页Power System Protection and Control

基　　金：国家自然科学基金项目(51507064)~~

摘　　要：柔性直流输电(VSC-HVDC)由于其特殊的控制系统和结构,线路故障后故障电流上升快,极易损坏换流器件。在行波保护基本原理的基础上,研究采样率对于保护灵敏性的影响。仿真分析发现,合适的高采样率可以显著提高行波保护的灵敏性。配合以极波变化率作为保护启动判据,以极波斜率区分雷电干扰和短路故障,以极波差值构造故障选极判据,提出一种适用于柔性直流输电线路的改进行波保护。在PSCAD/EMTDC平台上对双端柔性直流输电系统进行仿真分析,仿真结果验证了该新型行波保护具有良好的灵敏性,并且具有较强的抗干扰能力。Due to the special control system and structure of the VSC-HVDC system, as there is a line fault, the fault current rises quickly and the converter device can be damaged easily. In this paper, the influence of sampling rate on the sensitivity of protection is studied based on the basic principle of traveling wave protection. Simulation analysis shows that the appropriate high sampling rate can improve the sensitivity of traveling wave protection significantly. It presents an improved wave protection which uses pole-wave variance-ratio as the start criterion, adopts the pole-wave slope as a criterion to distinguish lighting interferences and short circuit faults, and employs the pole wave difference value to detect the fault pole. The simulation analysis of a two-terminal VSC-HVDC on PSCAD/EMTDC platform validates that the new wave protection has good sensitivity and strong anti-interference ability.

关 键 词：柔性直流输电 直流线路 行波保护 采样率 PSCAD/EMTDC 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM743