辐射状配电网接地故障诊断方法研究

【作者】 李绍文；

【导师】 束洪春；

【作者基本信息】 昆明理工大学 ， 水利水电工程， 2003， 硕士

【摘要】 快速、准确的故障定位是迅速隔离故障和恢复供电的前提，对于维护配电网的安全运行具有重要意义。而配电网的单相接地故障定位长期以来是难以解决的课题。论文对国内外关于该课题的现有的各种研究情况做了全面深入的分析，在此基础上从接地故障测距算法和在线监测两方面进行了研究。 基于对配电网发生单相接地故障后的故障主要特征的分析，论文应用加信诊断方法，提出了相应的接地故障定位算法。首先论文对三相均匀换位线路的故障定位进行了公式推导和数值计算分析，并在频域内对故障函数的频谱曲线幅值、相角和频率特性进行了分析，提出了相应的故障定位判据。经过数值仿真计算分析表明，该方法对直配线的接地故障定位是有效的，对树形多分支线路的故障定位理论上也是可行的，但实际应用中还有许多重要问题需要进一步深入研究。其次论文基于辐射状馈线的任一分支线路发生接地故障，通过分析与推导，建构了配电线路单相短路点定位的故障定位函数和相应的故障判据，利用树网单端信息完成故障分支识别、故障定位和过渡电阻定值。大量故障测距的数值仿真计算分析表明，该方法对配电网的接地故障定位是有效的。基于此论文还编制了单相接地故障定位的计算机通用程序。该测距算法不受负载参数变化的影响，不受接地过渡电阻值大小的影响。利用馈线首端测量信息实现故障测距，测距装置不需通信，不需实时监测，实际应用成本较低，因此具有较好的发展前景。 可实现接地故障区段自动检测与隔离的馈线自动化技术是配电网自动化的发展方向。通过对配电网发生单相接地故障后馈线的电压、电流变化规律的分析，论文提出了基于馈线现场监控终端FTU的故障点智能定位方法。该方法以馈线电压变化量为故障点定位的主要判据进行故障点自动监测与定位，并迅速隔离故障区段，恢复正常区段的供电。该方法与单独采用电流的电流型方法相比，可靠性更高，且不受系统接地方式的影响，能适用于较复杂的网络结构。更多还原

【Abstract】 Quick and accurate fault location is the premise to rapidly isolate the fault and redelivery power supply, and it is important to the normal working of power networks. Line-to-ground fault location maintains unresolved to power distribution networks for a long time. After a comprehensive analysis of existing methods, the author made a thorough study with the on-line monitoring method and a fault location algorithm.Based on the main fault-character analysis of single line-to-ground fault in non-grounded distribution networks, the location algorithms by injecting current are proposed for diagnosing and locating faults. Firstly, a relevant algorithm is presented for locating single-line-to-ground(SLG) fault in distribution networks, fault functions are reasoned out and analyzed for single-phase and three-phase distribution lines, and criterion measure, which are based on the frequency, phase and shape characteristics of the fault function spectrums , are also presented for locating SLG faults. Computer simulation shows that the criterion measure effectively locates faults in direct distribution line, and it is also feasible to tree-type distribution system in theory but there are still some problems in practice. In the next place, an improved algorithm of grounding fault location for tree-type distribution system which is based on new fault function and criterion measure, is proposed in order to complete fault branch identification, fault location and fault value. A lot of the simulation of fault diagnosis and location by computer demonstrate that the algorithm is effective. Universal computer program of locating SLG faults in distribution networks is worked but based on the algorithm. Since it is immune to load change, immune to the value of grounded resistance change and its parameters can be easily measured, the fault location algorithm can be widely applied to the power distribution networks.Feeder automation, which can automatically detect and isolate the ground-faulty section, is the direction distribution automation made progress to. An automatic fault location method is proposed based on FTU after the circuit analysis of single line-to-ground fault in distribution networks. In the method zero sequence voltage is discussed and new principle for automatic fault location and isolation based on the zero sequence voltage is presented in this paper. Compare to the traditional current methods, this method is not only immune from neutral grounding modes, but also more bearable to interference.更多还原