title: "Thermal Stabilization Effect" of Al2O3 nano-dopants improves the high-temperature dielectric performance of polyimide.
abstract: Insulation performance of the dielectrics under extreme conditions always attracts widespread attention in electrical and electronic field. How to improve the high-temperature dielectric properties of insulation materials is one of the key issues in insulation system design of electrical devices. This paper studies the temperature-dependent corona resistance of polyimide (PI)/Al2O3 nanocomposite films under high-frequency square-wave pulse conditions. Extended corona resistant lifetime under high-temperature conditions is experimentally observed in the 2 wt% nanocomposite samples. The "thermal stabilization effect" is proposed to explain this phenomenon which attributes to a new kind of trap band caused by nanoparticles. This effect brings about superior space charge characteristics and corona resistance under high temperature with certain nano-doping concentration. The proposed theory is experimentally demonstrated by space charge analysis and thermally stimulated current (TSC) tests. This discovered effect is of profound significance on improving high-temperature dielectric properties of nanocomposites towards various applications.
authors.affiliation: State Key Laboratory of Power System, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Power System, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Jinliang
authors.initials: J
authors.lastname: He
authors.affiliation: School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China.
authors.forename: Guangning
authors.initials: G
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Power System, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Hu