If the internal shielding structure is adopted in stator coil of turbogenerator, the maximum electric field strength can be reduced obviously and the electric field distribution of insulation can be improved. The 3D plotting software ProE has been used for building the models of stator coil with structure of insulation mastic, semiconductor adding copper strap, semiconductor mastic and conductive tape strip, the FEM software has been used for calculating the electric field of these types,and the resistance loss has been analyzed. It shows that the structure type of semiconductor adding copper strap is the best; if semiconductor and conductor electrically contact at only one point, the electric field distribution of insulation can be much better; and the resistance loss of semiconductor is much little, and so can be ignored.%大型汽轮发电机定子线圈的槽部采用内屏蔽结构,可以显著降低绝缘层的最大电场强度,均化绝缘层的电场分布.本文采用ProE三维制图软件建立了绝缘腻子、低阻带加铜带、导电腻子和半导电帽子4种内屏蔽结构的定子线圈模型,采用有限元分析软件计算了这4种结构形式下绝缘层的电场分布情况,并计算分析了其内屏蔽层的电阻损耗.计算分析表明,铜带加低阻带的结构形式是比较理想的内屏蔽结构形式;内屏蔽层与定子线棒有且仅有一点电接触时,绝缘层会获得比较好的电场分布;内屏蔽层的电阻损耗相对于定子线棒是比较小的,可以不予考虑.
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