| 摘要: |
| 针对传统高压直流输电线路双端测距依赖高精度同步对时，对通信通道要求较高的问题，提出利用故障行波线模、零模分量在线路中的传输时差来计算故障距离的双端测距方法。该方法通过提取故障行波两种模态分量的暂态信息，检测两种模量分别到达线路两端处的时刻，利用两者的时间差实现故障定位，克服了因两端检测装置时钟不同步所引起的误差。对于线模零模波速难以确定的问题，利用数学方法结合仿真数据拟合出波速曲线，再通过多次迭代过程不断对行波波速和故障距离进行优化，最后得到更准确的行波模量波速和故障距离值。在PSCAD／EMTDC仿真平台中搭建系统仿真模型，模拟时间不同步、不同故障距离和过渡电阻情况下的输电线短路状况，通过分析仿真，结果表明该方法定位准确性高，耐过渡电阻能力强，且不受时间不同步影响，具有良好的稳定性。 |
| 关键词: 模量传输时间差 行波故障测距 高压直流输电线路 |
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| Two-terminal Fault Location of DC Line Based on Modulus Transmission Time Difference |
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LIU Qun
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School of Electrical and Information Engineering,Anhui University of Science and Technology, Anhui Huainan 232001, China
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| Abstract: |
| In order to solve the problem that traditional HVDC transmission lines have high requirements on communication channels when they rely on high-precision synchronous pairs, a two-terminal location method was proposed to calculate the fault distance by using the transmission time difference between fault traveling wave line mode and zero mode component in the line. The method extracted the transient information of the two modal components of the fault traveling wave,detected the moment when the two modal components arrived at the two ends of the line, and used the time difference between them
to achieve fault location,overcoming the error caused by the unsynchronized clocks of the detection devices at both ends. For the problem that it was difficult to determine the wave speed of line-mode and zero-mode,the wave speed curve was fitted by mathematical methods combined with simulation data,and then the line wave speed and fault distance were continuously optimized through multiple iterations. Finally, more accurate values of the traveling mode wave speed and fault distance were obtained. A system simulation model was built in the PSCAD/EMTDC simulation platform to simulate the short-circuit condition of transmission lines under the condition of time asynchronism, different fault distances,and transition resistance. Through analysis and simulation, the results show that the method has high positioning accuracy, strong resistance to transition resistance, and good stability without the influence of time asynchronism. |
| Key words: modulus transmission time difference traveling wave fault location high voltage direct current(HVDC) transmission lines |
