ABSTRACT The influence of materials of mineral-insulated (MI) cables on their electrical characteristics upon exposure to high-temperature conditions was examined via a transmission test, in the objective of achieving the stability of the potential distribution along the cable length. Occurrence of a voltage drop along the cable was confirmed for aluminum oxide (Al2O3) and magnesium oxide (MgO), as insulating materials of the MI cable. A finite-element method (FEM)-based analysis was performed to evaluate the leakage in the potentials, which was found at the terminal end. Voltage drop yields by the transmission test and the analysis were in good agreement for the MI cable of Al2O3 and MgO materials, which suggests the reproducibility of the magnitude relationship of the experimental results via the FEM analysis. To suppress the voltage drop, the same FEM analysis was conducted, the diameter of the core wires (d) and the distance between them (l) were varied. Considering the variation of d, the potential distribution in the MI cable produced a minimum voltage drop corresponding to a ratio d/D of 0.35, obtained by dividing d with that of the insulating material (D). In case of varying l, a minimum voltage drop was l/D of 0.5.

中文翻译：

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矿物绝缘电缆压降分析及漏电抑制设计

摘要 通过传输测试研究了矿物绝缘 (MI) 电缆材料在暴露于高温条件下对其电气特性的影响，目的是实现沿电缆长度的电位分布的稳定性。对于作为 MI 电缆绝缘材料的氧化铝 (Al2O3) 和氧化镁 (MgO)，已确认沿电缆出现电压降。执行基于有限元方法 (FEM) 的分析以评估在终端发现的电位泄漏。对于 Al2O3 和 MgO 材料的 MI 电缆，传输测试和分析的电压降产量非常一致，这表明通过 FEM 分析的实验结果的大小关系具有可重复性。为了抑制压降，进行了相同的 FEM 分析，芯线的直径 (d) 和它们之间的距离 (l) 是不同的。考虑到 d 的变化，MI 电缆中的电位分布产生了对应于 d/D 比率为 0.35 的最小电压降，该比率是通过将 d 除以绝缘材料 (D) 得到的。在改变 l 的情况下，最小电压降为 l/D 为 0.5。