GIS母线损耗发热状况的电磁场与流场计算分析

Electromagnetic Field and Fluid Field Calculation and Analysis About the Loss and Heat of GIS Bus Bar

为准确分析气体绝缘组合电器(gas insulated switchgear,GIS)母线的损耗发热问题,运用有限元方法,以单相GIS母线为例,建立其损耗发热的电磁场与流场求解模型。在综合考虑集肤效应、涡流损耗、电导率温度效应、气体流动、以及重力等多种因素影响的基础上,计算分析单相GIS母线的热源和温度分布规律,并与实测数据进行比较。结果表明:对于水平放置的单相GIS母线,无论是在母线导体还是金属外壳中,电流和损耗的分布都体现出集肤效应,等温线分布并非一族沿半径方向温度单调下降的同心圆,母线导体与金属外壳的温度分布体现出上高下低,左右对称的规律,其内部环状空间气体对流作用较强,等温线呈弯曲的S型分布,同一圆周上温度分布并不均匀。

In order to analyse the loss and heat problems of of gas insulated switchgear(GIS) bus bar accurately,the electromagnetic field model and the fluid field model of the bus were established by finite element method.As an example, the losses and temperature of the single-phase GIS bus were calculated and analysed,and the influences of some factors such as skin effect and eddy loss,the electro-conductivity temperature effect,the gas flow and the gravity were considered.Furthermore,the data were compared with the test. The results show that the current and loss density distribution in the conductor and tank indeed follow skin effect,and for the horizontal single-phase GIS bus bar,the temperature of the top of conductor and tank is higher than the bottom,the distribution of temperature is symmetrical to the vertical center axis,the gas convection is fairly strong between the conductor and tank,and in that annulus,the shape of isothermals like'S', the temperature distribution is nonuniform at the same circumference of a circle.