基于非线性阻抗模型的含DG配电网故障测距研究

发布时间：2019-04-21 17:04

【摘要】：配电网故障测距的研究一直都是电力系统重要的课题之一。随着分布式发电(!)技术的发展,分布式电源(")与常规电力系统并网的趋势越来越明显。分布式发电(!)接入配电网后,配电网由单电源辐射状网络变成了多电源供电的复杂网络,这使基于馈线终端单元(#)的配电网自动化的馈线保护、故障定位方案变得更加复杂。适应配电网结构的这种变化,含有分布式电源的配电系统故障定位问题将是一个很大的挑战。对含!配电网故障测距进行研究有利于尽快恢复供电、减少停电损失,并且具有重要的应用价值。本文针对现有含!配电网故障测距方法的不足,对含!配电网故障的精确测距方法进行研究,提出了一种基于考虑量测数据的随机性、接地电阻的非线性和网络负荷的非线性的非线性阻抗模型的含!配电网故障测距新方法。本文首先应用复相关戴维南等值法和强跟踪滤波器求取系统主电源及各!的三相阻抗等效模型,考虑负荷的非线性,建立系统的三相不对称阻抗模型。其次,分析并提取含!配电网三相不对称阻抗模型下的故障特征,并依据各节点故障特征值判定故障区间。最后,在本文所建立的三相不对称阻抗模型以及所得故障区间的基础上,以故障距离和故障线路为变量,以故障节点的故障特征值为适应度函数,利用参数自适应差分进化算法对故障条件进行自动搜索,找到故障特征值最小时的故障距离即为精确故障测距结果。本文提出的基于非线性阻抗模型的含!配电网故障测距方法能够克服测量数据不确定性所带来的误差,所建的系统三相阻抗模型与实际配电网模型更加一致。仿真结果表明,该方法具有测距准确度高、鲁棒性强和计算速度快等优点,适用于电缆线路与架空线路组成的任何含!配电网的快速故障定位。
[Abstract]:The research of distribution network fault location has always been one of the important issues in power system. With distributed power generation (!) With the development of technology, the trend of grid connection between distributed power supply (") and conventional power system is becoming more and more obvious." Distributed generation (!) After connecting to the distribution network, the distribution network changes from a single-source radial network to a complex multi-source power supply network, which makes the feeder protection of distribution network automation based on feeder terminal unit (#) more complex and the fault location scheme more complicated To adapt to the change of distribution network structure, the problem of distribution system fault location with distributed power supply will be a great challenge. Yeah, Ham! The study of distribution network fault location is helpful to restore power supply as soon as possible, reduce the loss of power outages, and has important application value. This article addresses the existing include! Distribution network fault location method deficiencies, including! The precise fault location method of distribution network is studied, and a nonlinear impedance model based on the randomness of measured data, the nonlinearity of grounding resistance and the nonlinear impedance model of network load is proposed. A new fault location method for distribution network. In this paper, the complex correlation Thevenin equivalent method and strong tracking filter are used to obtain the main power supply and each power source of the system. The three-phase impedance equivalent model of the system is established, considering the load nonlinearity, and the three-phase asymmetric impedance model of the system is established. Secondly, analyze and extract the content! The fault characteristics under the three-phase asymmetrical impedance model of distribution network are analyzed, and the fault interval is determined according to the fault eigenvalues of each node. Finally, on the basis of the three-phase asymmetric impedance model and the fault interval obtained in this paper, the fault distance and fault line are taken as variables, and the fault eigenvalue of the fault node is taken as the fitness function. The parameter adaptive differential evolution algorithm is used to search the fault conditions automatically, and the fault distance with the smallest fault eigenvalues is found to be the accurate fault location result. In this paper, the nonlinear impedance model based on the inclusion! The fault location method of distribution network can overcome the error caused by the uncertainty of measurement data, and the three-phase impedance model of the system is more consistent with the actual distribution network model. The simulation results show that the proposed method has the advantages of high ranging accuracy, strong robustness and fast computing speed. It is suitable for any cable line and overhead line. Fast fault location of distribution network.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM727

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