地下电缆群暂态温度场和短时载流量数值计算方法

Numerical Method to Calculate the Transient Temperature Field and Short-Term Ampacity of Underground Cable System

利用有限差分法将地下电缆群暂态过程分为离散的时间步,然后利用有限元法分析每一时间步的地下电缆群温度场分布,给出了土壤直埋电缆群的暂态温度场分布。在此基础上,利用牛顿迭代法计算了土壤直埋电缆群的短时载流量。试验和计算结果表明,利用有限差分和有限元计算地下电缆群暂态温度场和短时载流量为工程实际提供了一种新的计算方法。

Finite difference method （FDM） is used to divide the transient temperature calculation process of underground cable systems into discrete groups of transient time step, and finite element method （FEM） is used to calculate each time step-temperature distribution of underground cable systems, and the transient temperature distribution of underground cable systems is calculated. Based on the calculation of the transient temperature distribution, short-term ampacity of underground cable systems is calculated by Newton iteration method. The result of test and calculation show that the method with FEM and FDM is an effective method to calculate the transient temperature field and short-term ampacity of underground cables in engineering.