电缆沟敷设方式下电缆载流量计算及其影响因素分析

Calculation of trench laying cable ampacity and its influencing factors

根据传热学的基本原理,利用有限单元自动划分法,建立了一种基于有限元法的电缆载流量计算模型,能按照实际敷设情况的变化对模型参数进行修改。根据电缆的结构参数和周围敷设区域的物性参数分析了电缆沟中电缆区域温度场分布情况,并提出基于二分法计算电缆载流量的方法。对比分析结果表明,相对于IEC60287中的热路法,该模型不仅计算结果准确,而且能更方便地考虑外界环境因素对电缆载流量的影响。通过实例仿真得出不同影响因素对电缆温度场分布的影响规律,并验证了该模型的准确性和可靠性。

According to the basic principle of heat transfer theory,a calculation model of cable ampacity is established based on the finite element method.Its parameters can be modified conveniently according to the actual situation.Based on the structural parameters of cable and the physical parameters of laying area,the temperature distribution of cable trench is analyzed and the dichotomy is proposed to calculate the cable ampacity.Analytical results show that,compared to IEC60287,the established model is more accurate and easier to include the influence of environmental factors.The impact law of different influencing factors on cable ampacity is obtained by case simulation,demonstrating the correctness and reliability of the model.