利用零模电流的VSC-HVDC输电线路单端量保护原理研究  

A novel protection method for VSC-HVDC transmission lines using single-end zero-mode current

作　　者：宋国兵[1] 冉孟兵[2] 靳幸福[3] 齐倩[1] 刘甜[1] 万青[1] 

机构地区：[1]西安交通大学电气工程学院,陕西西安710049 [2]国网重庆市电力公司江北供电分公司,重庆401147 [3]国网安徽省电力公司经济技术研究院,安徽合肥230022

出　　处：《电力系统保护与控制》2014年第15期1-7,共7页Power System Protection and Control

基　　金：国家自然科学基金项目(51177128);国家博士点基金资助项目(20110201110056)~~

摘　　要：电压源换流器型直流输电(Voltage Source Converter HVDC,VSC-HVDC)控制系统复杂,故障承受能力差,研究适用于VSC-HVDC系统的高性能保护十分必要。分析了三相两电平VSC-HVDC系统的结构特性及VSC-HVDC系统的零模网络,并在此基础上提出了一种单端电气量保护。该方法仅需单端电流量,对直流线路一端正负极电流之和进行积分得到零模电流,根据零模电流的幅值大小可以判断出区内单极故障,适用于正负极对称运行的三相两电平VSC-HVDC系统。算法简单可行,在时域进行,计算量小,对采样率要求低。利用PSCAD搭建VSC-HVDC系统进行仿真,仿真结果表明,该原理能够快速可靠地动作区内单极故障。As the control system of Voltage Source Converter HVDC（VSC-HVDC） is very complex, its resistance to fault is poor. It＇s necessary to do research on the protection of VSC-HVDC. This paper analyzes the structural characteristics and zero-mode network of VSC-HVDC, and proposes a single-end protection further. The proposed method needs only single-end zero-mode current which is obtained by integrating the sum of negative pole and positive pole currents. And the amplitude is used to distinguish internal single-pole-to-ground fault. The method applies to three-phase two-level VSC-HVDC system at positive and negative pole symmetrical operation status. The algorithm is very simple and implemented in time domain, needs fewer amount of computations, and its sampling frequency is lower. The PSCAD is used for fault simulation. Simulation results show that the proposed protection principle can find the internal single-pole-to-ground fault reliably and rapidly.

关 键 词：电压源换流器型直流输电 输电线路 单极故障 单端电流 零模电流 继电保护 

分 类 号：TM773[电气工程—电力系统及自动化]