摘要
在大电流运行条件下,欧姆损耗是特高压换流变压器穿墙套管封堵发热的重要因素。基于有限元法建立套管与封堵挡板的计算模型,计算得出封堵挡板的欧姆损耗。通过改变内外挡板是否通过接地线相连、挡板厚度、磁导率、电阻率,挡板与套管接触类型,分析上述因素对封堵挡板欧姆损耗的影响。通过计算得出内外挡板是否通过接地线连接对挡板欧姆损耗影响很小,因此,可在计算模型中忽略接地线。随着挡板厚度的增加,挡板总的欧姆损耗大致呈现增长趋势,但平均欧姆损耗显著下降。在挡板厚度较小,相对磁导率小范围变化时,挡板的磁导率对欧姆损耗的影响较小。随着挡板电阻率的增加,其欧姆损耗呈现先增后减的趋势,并在相对电阻率为0.5时达到最大值。当挡板与套管存在部分接触时,挡板本身的欧姆损耗也会有所增加。挡板与套管的接触部分虽然体积小,但其平均欧姆损耗可达挡板的10倍以上,极有可能导致接触部分的局部发热,此外不同类型的接触部分其欧姆损耗略有差异。计算结果可为换流变穿墙套管封堵的选材和施工提供理论基础和借鉴。
Under the condition of high current operation,ohmic loss is an important factor for plugging overheating of UHV converter transformer. Based on FEM,the calculation model of wall bushing and plugging baffle is established,and the ohm loss of plugging baffle is calculated. By changing the inner and outer baffles are connected by grounding wire or not,the thickness of baffle,permeability,resistivity,and the contact type between baffles,the influence of the above factors on ohm loss of plugging baffle is analyzed. The results show that whether the inner and outer baffles are connected by grounding wires has little influence on the ohm loss of baffles. Therefore,the grounding wires can be ignored in the calculation model. With the increase of baffle thickness,the total ohm loss of the baffle increases,but the average ohm loss decreases significantly. When the thickness of baffle is small and the relative permeability changes in a small range,the influence of permeability on ohm loss is small. With the increase of the resistivity of the baffle,the ohm loss increases and then decreases,and reaches the maximum value when the relative resistivity is 0. 5. When there is partial contact between the baffle and the bushing,the ohm loss of the baffle will also increase. Although the contact part between baffle and bushing is small,its average ohm loss is more than 10 times that of baffle,which is likely to cause local heating. In addition,the ohm loss of different contact parts is slightly different. The calculation results can provide theoretical basis and reference for the selection of plugging material and construction.
作者
陶瑞祥
董雪松
骆阗彦
胡俊华
TAO Ruixiang;DONG Xuesong;LUO Tianyan;HU Junhua(State Grid Zhejiang Electric Power Research Institute,Hangzhou 310014,China;State Grid Zhejiang Electric Power Company,Hangzhou 310007,China)
出处
《电瓷避雷器》
CAS
北大核心
2021年第2期135-141,共7页
Insulators and Surge Arresters
