Technical advantage of nanocomposite insulator for DC power equipment

为了阐明纳米复合材料的直流电绝缘材料的适用性，各种电气特性和直流介电击穿机制进行了研究。结果表明，MgO/LDPE纳米复合材料是一种上级的直流电绝缘材料，即使在高电场下，其导电电流也较低，直流击穿强度较高。结果表明，MgO纳米填料对直流击穿机理的作用是对同质空间电荷的俘获效应，从而降低了导电电流，提高了直流击穿耐受能力。此外，研究了一种有效的纳米结构电绝缘材料。结果表明，在氧化铝/环氧树脂复合材料中引入纳米孔结构，可以得到介电常数较低的绝缘材料。

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.