Dielectrically graded insulation (DGI) serving as an embodiment of functionally graded materials in electrical insulation field displays extraordinary insulation strength compared with conventional uniform composite materials. In recent years, the design and fabrication of DGI toward industrial applications have become urgent issues. Here, we reported a construction strategy of DGI for gas-insulated equipment. A topology optimization method was applied to optimize the electric ( EE ) field distribution of a 126-kV disk-type spacer with actual size. The spatial distribution of relative permittivity ( εr\varepsilon _{r} ) inside spacer was designed to improve the EE -field distributions along the spacer surface and near the triple junction region. Influences of design parameters on εr\varepsilon _{r} distributions and the resultant EE -field mitigation degree were analyzed. Appropriate values of design parameters that balance the structure processability and EE -field mitigation results were selected. A three-layer dielectrically graded spacer, including high, medium, and low εr\varepsilon _{r} regions, was constructed based on the topology optimization results. In addition, the influence of the area of design domain on the optimization results was analyzed. Numerical results indicate that the EE -field distribution of designed dielectrically graded spacers is significantly improved compared with that of a homogeneous spacer. In the situation with simplified electrode configuration, the maximum EE -field strength along the spacer and at triple junction area could be decreased by 10.5% and 43.4%, respectively. This three-layer DGI construction strategy is promising to apply industrially.

中文翻译：

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用于 126 kV GIS 的介电分级垫片：设计和施工策略


介电梯度绝缘（DGI）作为电绝缘领域功能梯度材料的体现，与传统的均匀复合材料相比，表现出非凡的绝缘强度。近年来，面向工业应用的DGI的设计和制造已成为紧迫的问题。在此，我们报道了气体绝缘设备的DGI建设策略。采用拓扑优化方法对实际尺寸的 126 kV 盘式间隔器的电场分布进行优化。间隔件内部相对介电常数 ( εr\varepsilon _{r} ) 的空间分布旨在改善沿间隔件表面和三结区域附近的 EE 场分布。分析了设计参数对 εr\varepsilon _{r} 分布和由此产生的 EE 场缓解程度的影响。选择平衡结构可加工性和EE场缓解结果的适当设计参数值。根据拓扑优化结果构建了三层介电梯度间隔物，包括高、中、低 εr\varepsilon _{r} 区域。此外，还分析了设计域面积对优化结果的影响。数值结果表明，与均匀间隔件相比，所设计的介电梯度间隔件的EE场分布显着改善。在简化电极配置的情况下，沿间隔物和三联结区域的最大EE场强度可分别降低10.5%和43.4%。这种三层DGI构建策略有望在工业上应用。