摘要
绝缘击穿是高性能工程电介质材料发展的关键基础科学问题.顺应第三代电网的发展要求,超/特高压交直流电力设备、智能电网、电力物联网和极端条件下电力设备的需求对工程电介质的击穿性能提出了更高的要求.本文综述了工程电介质材料击穿的研究现状,围绕电介质击穿和理论机理、性能演变规律、性能改善提升、新型高性能纳米复合电介质和聚合物微观分子设计/调控等内容展开论述.首先,基于电介质击穿和劣化的时空层次关系,论述了强场空间电荷击穿以及能量累计效应,拓展了电、热、电-机械击穿理论.其次,阐述了电介质击穿特性以及统计分析规律,分析了聚合物电介质本征击穿场强与温度、电压形式、空间电荷积聚和试样厚度的关系.再次,论述了高性能电介质材料的击穿特性以及性能调控方法;阐释了纳米复合电介质的研究现状和界面区作用机理,分析了聚合物微观分子设计的调控方法,以及对击穿的改性作用.最后,结合未来电力设备的发展需求,总结了高击穿性能电介质的关键问题和发展趋势,为新能源电力系统中工程电介质的发展提供依据和思路.
Insulation breakdown is the key basic scientific issue in the development of high-performance engineering dielectric materials.With the development requirements of the third-generation power grid,super/UHVAC-DC(alternating currentdirect current)power equipment,smart power grid,power internet of things and power equipment under extreme conditions present higher requirements on the engineering dielectrics with excellent breakdown performance.This paper summarizes the research status of the breakdown in engineering dielectric materials and discusses the theoretical mechanism of dielectric breakdown,the performance evolution,performance improvement,new high-performance nanocomposite dielectric,and micro molecular design/regulation.Firstly,based on the time-space hierarchical relationship of dielectric breakdown,the breakdown mechanisms related to the high field and energy accumulation effects are discussed.Moreover,the electric,thermal,electric and mechanical breakdown theory is extended.Considering the breakdown process of the actual dielectric,especially the polymer dielectric,and the complex factors,the current breakdown mechanism of the dielectric still has many problems.The electric breakdown is the main form of breakdown,which can explain the inducing and early process of breakdown.However,it is difficult to explain the formation and destruction of the breakdown channel.In addition,the breakdown mechanism may change as the thickness increases,requiring consideration of thermal or mechanical effects.Space charge can explain many of the characteristics of AC and DC breakdown,as well as the deterioration of dielectric materials,but when the thickness is small,the space charge is of limited use.Secondly,the dielectric breakdown characteristics and statistical analysis are expounded,and the relationship between the intrinsic breakdown field strength of polymer dielectric and temperature,voltage form,space charge accumulation,and sample thickness is analyzed.The breakdown strength of the material and the time require
作者
王威望
李盛涛
Weiwang Wang;Shengtao Li(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2020年第31期3461-3474,共14页
Chinese Science Bulletin
基金
国家自然科学基金(51337008,11575140,51707143)资助。
关键词
工程电介质
击穿
空间电荷
纳米复合电介质
分子设计
engineering dielectrics
breakdown
space charge
nanocomposite dielectric
molecular design
