考虑互热效应的超高压电缆隧道敷设热路模型  

Thermal Circuit Model of EHV Cable Laid in Tunnel Considering Mutual Thermal Effect

作　　者：马爱清 张杨欢 MA Aiqing;ZHANG Yanghuan(College of Electric Power,Shanghai University of Electric Power,Shanghai 200090,China)

机构地区：[1]上海电力大学电气工程学院,上海200090

出　　处：《高电压技术》2022年第3期1068-1076,共9页High Voltage Engineering

基　　金：上海市自然科学基金(19ZR1420600);上海绿色能源并网工程技术研究中心(13DZ2251900)。

摘　　要：针对IEC 60287标准计算电缆导体温度未考虑互热效应而导致结果存在偏差的问题,基于传热学理论考虑互热效应对散热系数的影响,提出了一种能准确快速计算隧道电缆导体温度的热路模型。根据电缆材料属性、安装方式、分组位置和环境确定了模型参数。基于该模型进一步提出500 kV超高压大截面电缆水平排列的总散热系数计算式,并得到了计算式的适应范围。通过总散热系数计算式可以迭代求解导体温度。将模型计算结果与IEC结果进行比较,并通过有限元热–流场耦合仿真进行验证。结果表明:模型计算结果与有限元仿真结果的误差小于2.5%。当电缆处于额定运行状态时,基于IEC标准计算的导体温度偏低,单根电缆偏差不大,可以不予考虑;三相电缆品字接触排列时最大温差达5℃;水平排列时最大温差达6℃,且随着电缆表面间距增大而减小,当电缆表面间距大于0.75倍电缆外径时互热效应可忽略不计。In view of the problem that the mutual heat effect is not considered in the calculation of cable conductor temperature in IEC 60287 standard,this paper proposes a thermal circuit model which can accurately and quickly calculate the temperature of tunnel cable conductor based on the heat transfer theory and considering the influence of mutual thermal effect on heat dissipation coefficient.According to the cable material properties,installation mode,grouping position and environment,the model parameters are determined.Based on the model,the total heat dissipation coefficient formula for horizontal arrangement of 500 kV extra high voltage(EHV)large section cables is further proposed,and the applicable range of the formula is obtained.The conductor temperature is obtained by the iterative calculation of the total heat dissipation coefficient formula.The results of the model are compared with the results of IEC and verified by the finite element method(FEM)thermal-fluid field coupling simulation.Ii is shown that the error between the results of model calculation and FEM simulation is less than 2.5%.When the cable is in rated operation state,the conductor temperature based on IEC standard is relatively low and the deviation of single cable is negligible,thus it can be ignored;the maximum temperature difference of three-phase cable is up to 5℃when the cable is touching trefoil formation;the maximum temperature difference is up to 6℃when the cable is in horizontal arrangement,and it decreases with the increase of cable surface distance.When the cable surface distance is greater than 0.75 times of cable outer diameter,the mutual thermal effect can be ignored.

关 键 词：超高压电缆 电缆隧道 互热效应 热路模型 热–流场耦合 

分 类 号：TM726.1[电气工程—电力系统及自动化]