大型汽轮发电机铜屏蔽优化设计研究

Optimization of Copper Shielding Design for Large Turbine Generators

大型汽轮发电机在额定和进相运行期间,由于定、转子绕组端部存在较大的漏磁场,易引起定子端部结构件产生损耗和发热问题。本文针对一台1100MW汽轮发电机在实际工程应用中出现的铜屏蔽局部温升过高问题,从增大磁阻降低涡流损耗和增大散热面积降低温升两个角度,对铜屏蔽进行了多个方案的优化设计,并采用三维瞬变场有限元法对优化方案和原方案在额定工况下的端部结构件损耗进行了计算对比,由此确定最终的铜屏蔽优化设计方案,解决了铜屏蔽底角温升过高的问题,具有一定的工程应用价值。

During the rated and in-phase operation of large turbine generators,the presence of large leakage magnetic fields at the stator and rotor winding ends can easily cause losses and heat generation problems in the stator end structural components.In this paper,to address the problem of high local temperature rise of the copper shield in a 1100MW turbine generator in actual engineering application,the design of the copper shield is optimised from the perspectives of increasing the magnetic resistance to reduce eddy current loss and increasing the heat dissipation area to reduce the temperature rise.The losses of the end structural members under rated operating conditions are calculated and compared between the optimised solution and the original solution using the 3D transient field finite element method.The final design of the copper shield is determined,which solves the problem of high temperature rise at the bottom corner of the copper shield and has certain engineering application value.