山火后输电导线力学和电学性能的研究

发布时间：2018-03-02 06:36

本文关键词： 山火输电导线拉伸强度载流量温度场　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：输电线路是电网输送电能的重要设备。近年来,我国电网输电线路山火频发,严重危害输电线路的安全运行。因此,对山火后输电线路导线的力学和电学性能研究显得尤为重要。本文以常用的架空输电导线(钢芯铝绞线)为研究对象,用山火模拟实验研究了温度对导线拉伸强度和载流量的影响;用有限元仿真分析了山火发生时导线的总长度、最大弧垂以及应力的变化。主要研究内容如下:(1)以薪柴火烧烤导线和管式电阻炉烘烤导线模拟山火烧导线,研究了温度对导线拉伸强度的影响。结果表明:柴火烧烤后,随着火烧程度的增加,整根导线或单丝导线的最大拉断力逐渐减小。管式电阻炉烘烤后,单丝铝线和钢芯的最大拉断力均随着烘烤温度的升高而减小;单丝铝线伸长率随着温度的升高而增大,单丝钢芯的伸长率随着温度的升高而减小。真实山火后导线的拉断力实验中,得出真实山火对导线外层的拉伸强度影响比较大,对中层和内层基本没有影响。(2)测量不同温度烘烤后导线的直流电阻,根据载流量计算公式,得出导线载流量和加热温度的关系。结果表明:导线无断股时,随着加热温度的升高,总体上导线的载流量略微增加,增幅在3%以内。在有断股情况时,经不同温度烘烤后的导线,在断股数相同时,载流量降低的百分比相同。(3)用ANSYS-CFX模拟山火火场,得出山火发生时导线上的温度场,继而计算得出山火发生时导线总长度、最大弧垂以及拉应力的变化。ABAQUS中在导线上施加同种温度进行静力分析,得出导线的总长度、最大弧垂、应力等参数随着温度的变化规律。结果表明:对于档距一定的导线,山火发生时,导线总长度、最大弧垂随温度的增加而增大,最低点拉应力随温度的增加而减小。以上结论为判断山火后导线能否继续正常运行提供了实验与分析参考依据。
[Abstract]:Transmission line is an important equipment for electric power transmission in power grid. In recent years, the mountain fire of power transmission line in our country is frequently occurring, which seriously endangers the safe operation of transmission line. It is very important to study the mechanical and electrical properties of transmission lines after hill fire. In this paper, the commonly used overhead transmission lines (steel core aluminum strands) are taken as the research object. The influence of temperature on the tensile strength and load flux of the wire was studied by using the mountain fire simulation experiment, and the total length of the conductor was analyzed by finite element simulation. The main contents of this study are as follows: 1) the effect of temperature on the tensile strength of the wire was studied by using firewood barbecue wire and tube resistance furnace to simulate the mountain fire wire, and the results showed that: after firewood barbecue, the effect of temperature on the tensile strength of the wire was studied. With the increase of burning degree, the maximum tensile force of the whole wire or single wire wire decreases gradually, and the maximum tensile force of aluminum wire and steel core decreases with the increase of baking temperature after baking in tubular resistance furnace. The elongation of monofilament aluminum wire increases with the increase of temperature, and the elongation of steel core decreases with the increase of temperature. The direct current resistance of conductors after baking at different temperatures is measured. According to the calculation formula of carrier flow, the relationship between lead flux and heating temperature is obtained. The results show that the conductors have no broken strands. With the increase of heating temperature, the overall carrying capacity of the wire increases slightly, with an increase of less than 3%. In the case of broken strands, the conductors baked at different temperatures have the same number of broken shares, Using ANSYS-CFX to simulate the fire field, the temperature field on the wire when the mountain fire occurs, and then calculate the total length of the wire when the mountain fire occurs. The variation of maximum sag and tensile stress. The static analysis of the same temperature applied in Abaqus shows that the total length, maximum sag, stress and other parameters of the wire vary with the temperature. The results show that: for the wire with a certain distance, When a hill fire occurs, the total length and maximum sag of the wire increase with the increase of temperature, and the lowest tensile stress decreases with the increase of temperature. The above conclusions provide an experimental and analytical reference for judging whether the wire can continue to operate normally after the fire.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM75

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