大电流开关柜温升及其影响因素的建模仿真研究

Modeling and Simulation Study of Temperature Rise and Related Influence Factors of High Current Switch Cabinet

随着中国电网容量的不断增大,用于输配电的开关柜数量也大大增加,这就对开关柜小型化和安全性能提出了更高的要求,而小型化的趋势使温升问题日益严重,加大了对安全性保障的难度。文中针对中压大电流开关柜的温升问题在SolidWorks和Ansys Workbench平台上进行了建模仿真研究。首先,基于电磁场理论,通过基于表面深度划分网格的方式进行了开关柜的涡流场仿真,分析了各个部分的损耗,研究了涡流损耗对总损耗的影响。随后运用单向耦合的方法进行了开关柜温度场的仿真,研究表明真空灭弧室触头中触头片部分是温升最严重的部分。最后结合涡流场与温度场仿真结果,进一步对开关柜在热源和散热两方面进行比较研究,结果表明将壳体材料改成不锈钢、触头片材料改为无氧铜(从发热的角度)、触头结构改为螺旋槽形橫磁触头、开关柜改善通风散热条件对开关柜的温升的降低具有明显的作用,仿真结果得到了实验验证。

With the continuous increase of capacity of power grid in China,the number of switch cabinet for power transmission and distribution also increased significantly,which puts forward higher requirement to the smart and safety performance of the switch cabinet. However,the smart trend makes temperature rise problem increasingly serious and the difficulty of security assurance is increased. In view of temperature rise issue of medium voltage high current switch cabinet in this paper,the modeling and simulation are performed on SolidWorks and Ansys on Workbench platform. Firstly,based on the electromagnetic field theory,the eddy current field is simulated by way of surface depth classification mesh,the loss of each part is analyzed and the influence of eddy current loss on total loss is studied. Then,the one-way coupling method is used to simulate the temperature field of the switch cabinet. The study shows that the portion of the contact piece of contact of vacuum interrupter is the most serious portion of temperature rise. Finally,with simulation result of eddy current and temperature field,the switch cabinet is compared and studied further from such two aspects of heat and radiation sources. The result shows that change of the housing material into stainless steel and the contact piece material into oxygen-free copper( from the point of view of heating),the contact structure into spiral groove shaped transverse magnetic contact and the improvement of radiation condition of the switch cabinet have remarkable effect in reducing the temperature rise of the switch cabinet.And the simulation result is verified by the experiment.