基于热力耦合的高压大截面电缆应力和形变研究

Research on Stress and Deformation of High Voltage Cable with Large Section Based on Thermal-mechanical Coupling

为了研究高压大截面电缆运行过程中受热产生的应力和形变,根据传热学和弹性力学基本理论,利用有限元方法建立高压大截面电缆热力耦合模型计算其应力及形变。根据计算结果得到电缆各层温度、应力和形变的分布特性。通过对不同负荷电流下的温度、应力和形变数据进行拟合,提出相应的快速计算公式。结果表明:导体与绝缘层交界面的接触应力最大;最大轴向形变出现在绝缘层;外护层与缓冲层的径向形变较大;温度、应力和形变可由与负荷电流相关的二次多项式进行快速计算。

In order to study the stress and deformation caused by heat during the operation of high voltage cable with large section, according to the basic theory of heat transfer and elasticity, a thermal-mechanical coupling model of high voltage cable with large section was established by finite element method to calculate its stress and deformation. The distribution characteristics of temperature, stress, and deformation in each layer of cable were obtained according to the calculation result. The data of temperature,stress, and deformation under different load currents were fitted, and the corresponding fast calculation formulas were proposed. The results show that the contact stress at the interface between conductor and insulation layer is the largest, the maximum axial deformation appears at the insulation layer, and the radial deformation of outer sheath and buffer layer are relatively large. The temperature, stress, and deformation can be quickly calculated by the quadratic polynomials related to the load current.