配电网电缆单相接地故障测距方法研究

发布时间：2018-06-15 21:38

本文选题：单相接地故障 + 故障分析法　；参考：《西安科技大学》2017年硕士论文

【摘要】：城区配电网中,电缆以其占地面积小、供电可靠性高、不易受环境影响等特点逐渐取代了架空线,成为主要供电线路。由于大多数电缆都敷设于电缆沟或埋于地下,故障不易查找,因此,准确的故障定位具有非常重要的意义。本文提出了简单易行的故障分析法,构建精确的测距方程,实现准确测距。建立了考虑高阶无穷小量的线路分布参数模型,该模型精确计及了线路参数的分布特性,满足了配电网电缆故障测距的要求。在该模型的基础上,依据从线路两端推算到故障点的零模电压瞬时值相等的原理,构造了故障测距方程,该方程是时域微分方程,适用于任意电压等级、线路参数以及长度的线路暂稳态分析。针对零模信号需要高阶求导的问题,为精确求取零模信号的高阶导数,本文提出了零模信号正弦逼近拟合的方法。该方法克服了差分近似代替微分求导误差大的缺陷,提高了测距的准确性。针对粒子群极值寻优算法缺乏局部区域的精细搜索能力,提出了采用粒子群-牛顿迭代融合的故障测距算法求解故障距离。并用ATP和MATLAB对不同仿真条件下的单相接地故障测距方法进行了仿真验证,结果表明了本文提出的测距方法的有效性和准确性。
[Abstract]:In the urban distribution network, the cable has gradually replaced the overhead line and become the main power supply line because of its small area, high reliability of power supply and not easy to be affected by the environment. Because most cables are laid in cable trenches or buried underground, it is difficult to find fault, so accurate fault location is very important. In this paper, a simple and easy fault analysis method is put forward, and the accurate location equation is constructed to realize the accurate location. A transmission line distribution parameter model considering high order infinitesimal quantities is established. The model accurately considers the distribution characteristics of line parameters and meets the requirements of cable fault location in distribution network. On the basis of the model, the fault location equation is constructed based on the principle of equal zero-mode voltage from both ends of the line to the fault point. The equation is a time-domain differential equation, which is applicable to any voltage level. The transient steady state analysis of line parameters and length. To solve the problem that high order derivative is needed for zero mode signal, in order to obtain the high order derivative of zero mode signal, this paper presents a method of sinusoidal approximation fitting of zero mode signal. This method overcomes the shortcoming of difference approximation instead of large differential derivative error and improves the accuracy of ranging. Aiming at the lack of fine searching ability of local region in particle swarm optimization algorithm, a fault location algorithm based on particle swarm optimization and Newton iteration fusion is proposed to solve the fault distance. The single-phase grounding fault location method under different simulation conditions is simulated by ATP and MATLAB. The results show that the proposed method is effective and accurate.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM862;TM75

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