Surface flashover is a gas-solid interface insulation failure that significantly jeopardises the secure operation of advanced electronic,electrical,and spacecraft applications.Despite the widespread application of num...Surface flashover is a gas-solid interface insulation failure that significantly jeopardises the secure operation of advanced electronic,electrical,and spacecraft applications.Despite the widespread application of numerous material modification and structure optimisation technologies aimed at enhancing surface flashover performance,the influence mechanisms of the present technologies have yet to be systematically discussed and summarised.This review aims to introduce various material modification technologies while demonstrating their influence mechanisms on flashover performances by establishing relationships among‘microscopic structure-mesoscopic charge transport-macroscopic insulation failure’.Moreover,it elucidates the effects of chemical structure on surface trap parameters and surface charge transport concerning flashover performance.The review categorises and presents structure optimisation technologies that govern electric field distribution.All identified technologies highlight that achieving a uniform tangential electric field and reducing the normal electric field can effectively enhance flashover performance.Finally,this review proposes recommendations encompassing mathematical,chemical,evaluation,and manufacturing technologies.This systematic summary of current technologies,their influence mechanisms,and associated advantages and disadvantages in improving surface insulation performance is anticipated to be a pivotal component in flashover and future dielectric theory.展开更多
Lightweight structures are widely used across different industry sectors.However,they get easily excited by external influences,such as vibrations.Undesired high vibration amplitudes can be avoided by shifting the str...Lightweight structures are widely used across different industry sectors.However,they get easily excited by external influences,such as vibrations.Undesired high vibration amplitudes can be avoided by shifting the structural eigenfrequencies,which can be achieved adapting the structural design considering optimisation procedures and structures primarily inspired by diatoms.This procedures has been applied to the development process of a girder structure installed in a synchrotron radiation facility to support heavy magnets and other components.The objective was to design a 2.9 m long girder structure with high eigenfrequencies,a high stiffness and a low mass.Based on a topology optimisation result,a parametric beam–shell model including biologically inspired structures(e.g.,Voronoi combs,ribs,and soft and organic-looking transitions)was built up.The subsequent cross-sectional optimisation using evolutionary strategic optimisation revealed an optimum girder structure,which was successfully manufactured using the casting technology.Eigenfrequency measurements validated the numerical models.Future changes in the specifications can be implemented in the bio-inspired development process to obtain adapted girder structures.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:52307166Natural Science Foundation of Heilongjiang Province,Grant/Award Number:LH2023E085+1 种基金Natural Science Foundation of Shandong Province,Grant/Award Number:ZR2023QE072State Key Laboratory of Electrical Insulation and Power Equipment,Grant/Award Number:EIPE23206。
文摘Surface flashover is a gas-solid interface insulation failure that significantly jeopardises the secure operation of advanced electronic,electrical,and spacecraft applications.Despite the widespread application of numerous material modification and structure optimisation technologies aimed at enhancing surface flashover performance,the influence mechanisms of the present technologies have yet to be systematically discussed and summarised.This review aims to introduce various material modification technologies while demonstrating their influence mechanisms on flashover performances by establishing relationships among‘microscopic structure-mesoscopic charge transport-macroscopic insulation failure’.Moreover,it elucidates the effects of chemical structure on surface trap parameters and surface charge transport concerning flashover performance.The review categorises and presents structure optimisation technologies that govern electric field distribution.All identified technologies highlight that achieving a uniform tangential electric field and reducing the normal electric field can effectively enhance flashover performance.Finally,this review proposes recommendations encompassing mathematical,chemical,evaluation,and manufacturing technologies.This systematic summary of current technologies,their influence mechanisms,and associated advantages and disadvantages in improving surface insulation performance is anticipated to be a pivotal component in flashover and future dielectric theory.
基金This study was financially supported by the Innovationsfonds from the Alfred Wegener Institute,Helmholtz Centre for Polar andMarine Research(AWI)and by the Deutsches Elektronen-Synchrotron(DESY),a research centre of the Helmholtz Association,christian.hamm@awi.de。
文摘Lightweight structures are widely used across different industry sectors.However,they get easily excited by external influences,such as vibrations.Undesired high vibration amplitudes can be avoided by shifting the structural eigenfrequencies,which can be achieved adapting the structural design considering optimisation procedures and structures primarily inspired by diatoms.This procedures has been applied to the development process of a girder structure installed in a synchrotron radiation facility to support heavy magnets and other components.The objective was to design a 2.9 m long girder structure with high eigenfrequencies,a high stiffness and a low mass.Based on a topology optimisation result,a parametric beam–shell model including biologically inspired structures(e.g.,Voronoi combs,ribs,and soft and organic-looking transitions)was built up.The subsequent cross-sectional optimisation using evolutionary strategic optimisation revealed an optimum girder structure,which was successfully manufactured using the casting technology.Eigenfrequency measurements validated the numerical models.Future changes in the specifications can be implemented in the bio-inspired development process to obtain adapted girder structures.
