基于热电类比及参数辨识的高压架空导线断股温升模型研究

发布时间：2019-01-07 14:51

【摘要】：高压架空导线长期受风振、雷击、覆冰和闪络等恶劣运行条件影响,易发生断股损伤现象,将导致局部线路异常温升。由于导线蠕变退火、材质劣化、线路弧垂计算和寿命预测等问题均与导线运行温度参数密切关联,构建计及断股损伤的高压架空导线温升模型,有助于评估导线断股和自身发热对导线运行状态的影响,并为上述问题的深入研究提供必要的理论基础,对高压输电线路状态监测及减灾防灾技术的发展具有重要意义。目前已有一些关于导线运行温度计算模型的研究,然而,现有模型主要针对无损导线建立,模型中参数较多且难以准确获取,计算时大多采用经验公式,计算结果存在一定的误差。此外,当前的温升模型均未能反映断股对导线温升特性的影响,导线的电参数和热参数在断股后都会发生不同程度的变化。为此,本文展开了相关研究。首先,本文以钢芯铝绞线LGJ-120/25和LGJ-240/30为研究对象,设计了高压架空导线断股实验平台,在不同电流等级和温度条件下对无损及断股导线交流电阻进行实测,并分析了导线交流电阻的非线性特性。为准确计算断股导线交流电阻值,建立了计及断股损伤的导线交流电阻计算模型,并对模型精度进行了验证。在此基础上,本文基于热电类比理论,提出了高压架空导线断股温升模型。利用导线断股实验平台,在不同断股数条件下,对LGJ-120/25导线和LGJ-240/30导线加载不同的电流等级进行载流温升实验。为克服所建模型参数难以确定的问题,对实验数据进行参数辨识,并分析了不同断股数条件下模型参数随电流变化的规律。通过实验验证分析,本文的断股温升模型计算结果与实验值较吻合,误差小,可准确描述断股导线温升热动态过程。
[Abstract]:High voltage overhead conductors are affected by bad operating conditions such as wind vibration, lightning strike, icing and flashover for a long time, which will lead to abnormal temperature rise of local lines. Due to the problems of creep annealing, material deterioration, line sag calculation and life prediction, which are closely related to the wire operating temperature parameters, a temperature rise model for high pressure overhead conductors with broken strands damage is constructed. It is helpful to evaluate the influence of wire strands breaking and self heating on the running state of conductors, and to provide the necessary theoretical basis for the further study of the above problems, which is of great significance to the development of HV transmission line condition monitoring and disaster mitigation and prevention technology. At present, there have been some researches on the calculation model of conductor operating temperature. However, the existing models are mainly aimed at the establishment of lossless conductors, and the parameters in the model are many and difficult to obtain accurately, and most of them are calculated by empirical formula. There is a certain error in the calculation results. In addition, the current temperature rise models fail to reflect the influence of broken strands on the temperature rise characteristics of conductors, and the electrical and thermal parameters of conductors will change in varying degrees after breaking the strands. For this reason, this article has carried out the related research. Firstly, taking the LGJ-120/25 and LGJ-240/30 of steel core aluminum strand as the research object, the experimental platform of high voltage overhead wire breaking is designed, and the AC resistance of nondestructive and broken wire is measured under different current levels and temperatures. The nonlinear characteristics of the conductor AC resistance are analyzed. In order to calculate the AC resistance of broken wire accurately, the model of AC resistance with broken strand damage is established, and the accuracy of the model is verified. Based on the theory of thermoelectric analogy, the model of temperature rise of high voltage overhead wire is presented in this paper. In this paper, the current temperature rise of LGJ-120/25 wire and LGJ-240/30 wire loaded with different current levels is studied by using the traverse breaking experiment platform under the condition of different number of broken strands. In order to overcome the problem that the parameters of the model are difficult to be determined, the parameters of the model are identified, and the variation of the model parameters with the current is analyzed under the condition of different broken shares. Through experimental verification and analysis, it is found that the calculated results of the model are in good agreement with the experimental values, and the error is small, which can accurately describe the thermal dynamic process of the broken wire.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM75

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