Technical advantage of nanocomposite insulator for DC power equipment

为了阐明纳米复合材料在直流绝缘材料中的适用性，研究了纳米复合材料的各种电学特性和直流介质击穿机理。结果表明，即使在较高的电场下，氧化镁/低密度聚乙烯纳米复合材料仍具有较低的导电电流和较高的直流击穿强度，是一种性能优良的直流绝缘材料。结果表明，氧化镁纳米薄膜对直流击穿机理的影响主要是同位空间电荷的俘获效应，从而降低了导电电流，提高了直流击穿的耐久性。此外，还研究了一种有效的电绝缘材料的纳米结构。结果表明，在氧化铝/环氧复合材料中引入纳米孔结构可以得到较低的介电常数绝缘材料。

In order to clarify the applicability of nanocomposite to DC electrical insulating material, various electrical characteristics and DC dielectric breakdown mechanisms were investigated. It was revealed that MgO/LDPE nanocomposite was a superior DC electrical insulating material, even under the high electric field, which had a lower electrical conduction current and higher DC breakdown strength. It was indicated that a role of MgO nanofillers on the DC breakdown mechanism was a trapping effect of homo space-charge, which could reduce the conduction current and enhance the DC breakdown endurance. Furthermore, an effective nanostructure to electrical insulating material was investigated. It was revealed that introduction of nano-porous structure to alumina/epoxy composite could lead the lower permittivity insulating material.