基于有限元法的电力电缆载流量计算

发布时间：2018-12-25 07:54

【摘要】：为使电缆线路长期稳定运行，且能充分发挥其传输能力，准确计算其载流量至关重要。影响电缆载流量的因素较多，尤其在多回路电缆集群敷设时，按照国际电工委员会（IEC）和国家标准应用解析法计算电缆的载流量往往误差较大。因此，研究基于计算机技术的电缆载流量核定新方法意义重大。本文建立了基于有限元法的电力电缆电磁场和温度场模型，考虑到导体电阻率与温度有关，在计算功率损耗体密度的基础上，建立了“电—热”间接耦合二维有限元模型，并以此模拟仿真电力电缆的载流量。首先仿真计算了单回路电缆在不同敷设条件下的载流量，通过将仿真结果与解析法计算（按IEC－60287标准）比较，验证了采用有限元法计算电力电缆载流量有效、可行，结果准确。在此基础上，仿真分析了空气温度、土壤温度、土壤热阻系数、电缆埋设深度、相邻电缆轴间距等因素对电缆的温度场分布以及载流量的影响。然后，以集群敷设的两回路和三回路电缆为研究对象，，仿真计算了在多回路平面排列和竖直排列时各电缆的载流量，对比了彼此间及与单回路敷设电缆间载流量的差异，分析了相关机理。采用有限元法模拟仿真电缆的载流量，可以全面考虑诸多复杂的影响因素，计算结果对保证电缆的安全、经济运行具有实际意义。
[Abstract]:In order to make the cable line run stably for a long time and give full play to its transmission capacity, it is very important to calculate the carrier current accurately. There are many factors affecting the cable load, especially in the multi-loop cable cluster laying, according to the (IEC) and the national standards of the International Electrotechnical Commission of the application of analytical method to calculate the cable load error is often large. Therefore, it is of great significance to study the new method of cable current checking based on computer technology. In this paper, the electromagnetic field and temperature field model of power cable based on finite element method is established. Considering that the resistivity of conductor is related to temperature, a two-dimensional finite element model of "electric-thermal" indirect coupling is established on the basis of calculating the volume density of power loss. The load current of power cable is simulated by this method. First, the load current of single loop cable under different laying conditions is calculated by simulation. By comparing the simulation results with analytical method (according to IEC-60287 standard), it is proved that the finite element method is effective and feasible to calculate the load current of power cable. The result is accurate. On this basis, the effects of air temperature, soil thermal resistance coefficient, cable embedding depth and the distance between adjacent cable axes on the temperature field distribution and load flow of the cable are simulated and analyzed. Then, taking the two-loop and three-loop cables laid in cluster as the research object, the load current of each cable in the multi-loop plane arrangement and vertical arrangement is simulated and calculated, and the difference of the carrier current between each other and between the single-loop laying cable is compared. The related mechanism is analyzed. The finite element method (FEM) is used to simulate the load current of the cable, and many complicated factors can be considered. The calculation results are of practical significance to ensure the safety and economic operation of the cable.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TM744

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