基于行波叠加特征分析的VSC-HVDC输电系统单端故障定位  

One-terminal Fault Location for VSC-HVDC Transmission Lines Based on the Feature of Overlapped Traveling Wave

作　　者：宋国兵[1] 李德坤[2] 靳幸福[1] 徐海洋[1] 郭润生 

机构地区：[1]西安交通大学电气工程学院,西安710049 [2]国网山东省电力公司济南供电公司,济南250012 [3]山西朔州供电分公司,朔州036002

出　　处：《高电压技术》2013年第11期2743-2749,共7页High Voltage Engineering

基　　金：国家自然科学基金(51177128;51037005);国家教育部博士点基金(20110201110056)~~

摘　　要：为保障电压源换流器型直流输电(voltage source converter HVDC,VSC-HVDC)系统的可靠运行,提出了一种利用行波叠加特征的VSC-HVDC输电线路单端故障定位方法。由于VSC-HVDC输电线路两端直流母线处并联有大电容,直流线路发生单极接地故障后,1模故障分量网络中的电压行波具有"直流母线处全反射,故障点处主要为折射,反射改变电压极性,折射不改变电压极性"的特点。据此在故障分量网络中以行波首次到达本端的时刻为起点,通过计算找出沿线电压前行波和反行波的最强叠加点,该叠加点到对端的距离即是故障距离。PSCAD下的仿真结果显示该方法的故障定位误差≤0.06%,耐过渡电阻能力可达300Ω。该仿真结果表明该方法的故障定位精度高,易于实现故障定位的自动化,在VSC-HVDC输电线路中具有一定的实用价值。In order to guarantee the reliable reliable operation of voltage source converter HVDC （VSC HVDC） system, we have proposed a one-terminal fault location algorithm for VSC-HVDC transmission lines based on travelling wave superposition. Because large capacitors are shunted on both terminals of the VSC-HVDC transmission lines, when a one-terminal ground fault occurs on the DC lines, the voltage travelling waves in the faulted component network of mode 1 have two features： they have total reflection at two-terminal DC buses, and refraction mainly at fault points; the reflection leads to alternation of the voltage polarity, but the refraction does not. Therefore, if taking the time when the first travelling wave arrived at the measuring point as the originating time, a fault can be located as the strongest overlapped point between forward and backward travelling waves through calculation. Then the distance from this overlapped point to the opposite terminal is the fault distance. PSCAD simulation results show that the proposed method has error less than 0.06% in locating faults, and can tolerate transition resistance up to 300%. It is concluded that this method is accurate in locating faults and helps to realize automatic fault location, so it can he adopted for VSC-HVDC transmission lines.

关 键 词：VSC—HVDC 单端电气量 故障定位 自动化 分布参数模型 电压行波 

分 类 号：TM73[电气工程—电力系统及自动化]