场路结合法求解地下高压电缆载流量  

Computation of Ampacity of Underground High Voltage Cables Based on Combination of Temperature Field and Heat Circuit

作　　者：周秧[1] 周晓虎[2] 谭春力[2] 袁忠君[2] 李长旭[2] 

机构地区：[1]浙江电力教育培训中心浙西分中心,浙江建德311600 [2]东北电力大学,吉林吉林132012

出　　处：《现代电力》2008年第1期49-52,共4页Modern Electric Power

摘　　要：研究了埋设于复杂土壤中的电力电缆在稳态及暂态情况下的温度场和载流量。土壤区域采用有限容积法离散传热方程,并采用交替方向块迭代法加快求解速度,在求得土壤的稳态温度场或暂态温度场的一个时步的收敛温度场后,与电缆区域的等值热路法相结合,最终求得电缆导电线芯的温度及载流量。通过在与电缆导电线芯同圆心的土壤圈上进行二次插值将数值计算求得的土壤区域温度场和电缆区域的等值热路计算结果联系起来。为了加快计算速度,土壤采用了不均匀网格。采用变导热系数将土壤水分迁移的影响和电缆各层材料导热系数随温度变化的影响考虑进来。有效地解决了土壤区域与电缆区域边界不一致给计算带来的困难,编程简单方便,计算速度快。通过与试验结果的比较,证明了方法的正确性。Temperature field and ampacity of underground cables in steady and transient conditions buried in complicated soil are studied. Finite volume method is used to discrete heat transfer equation. The alternate direction iteration method is used to accelerate the solving speed. When the steady temperature or convergent temperature of a time step of transient condition is obtained, with the combination of equivalent heat circuit method in the region of cables, the temperature of conductive core of cables and ampacity is obtained. The temperature field in soil is derived by numerical calculation. Results of heat circuits are connected by quadratic interpolation in the soil circuit which has the same center with the cables＇ core. In order to speed up the calculation, the uninformed mesh is applied. The effect of water transfer in soil and variation of conduction coefficient of each layer of cable are considered with variable conduction coefficients. The obstacle of boundary difference of soil area and cables＇ area is effectively overcome. The programming is simple and computation is fast. Experiment results are compared, which proves the validity and reliability of this method.

关 键 词：有限容积法 载流量 温度场 电力电缆 热路法 

分 类 号：TM726.4[电气工程—电力系统及自动化]