不受波速影响的特高压直流输电线路单端故障测距方法

现行特高压直流输电线路故障测距大多采用行波法,但单端/双端行波测距受行波波速影响较大,加上输电线路弧垂效应,测距精度较差。利用对端行波到达本端测距装置的时刻,通过公式推导消除行波波速的影响,推导出一种不受波速影响的特高压直流输电线路单端故障行波测距方法,将无需准确计算线路沿线波速也能实现直流输电线路故障测距。在PSCAD/EMTDC中搭建哈郑±800 kV特高压直流输电系统模型,在不同故障位置和不同过渡电阻下进行仿真。大量仿真结果表明,该改进单端测距方法不受输电线路沿线波速和故障位置影响且耐受过渡电阻能力强。

Single terminal fault location method of UHVDC transmission line immune to wave speed

The current UHVDC transmission lines mainly adopt traveling wave fault location method, but the single/double terminal traveling wave fault location is affected by the velocity and the transmission line sag effect, thereby such fault location has low accuracy. Based on the moment of the opposite terminal traveling wave arriving at the measuring terminal of location device, the influence of traveling wave velocity is eliminated through the formula derivation and single terminal fault location method for UHVDC transmission line is deduced which is not affected by wave velocity and can realize fault location without accurately calculating the velocity along the line. The model of Ha-Zheng ±800 kV UHVDC transmission system is built in PSCAD/EMTDC and simulated under different fault locations and different transition resistances. A large number of simulation results show that the improved single terminal ranging method is not affected by the wave speed along the transmission line and the location of the fault, and has the strong ability to tolerate transient resistance. This work is supported by Joint Natural Science Foundation of the Xinjiang Uygur Autonomous Region (No. 2017D01C028).