Improvement of Surface Flashover Performance in Vacuum of A-B-A Insulator by Adopting ZnO Varistor Ceramics as Layer A

Surface flashover is a devastating electronic avalanche along the gas–solid interface when a high electric field is applied, which is a potential issue that threatens the safe operations of advanced power electronic, electrical, and spacecraft applications. However, the underlying physical mechanisms for surface flashover development are still under investigation owing to the complex charge transport processes through the gas phase, solid phase, and gas–solid interface. In this study, the history of surface flashover theory in the last 50 years is introduced, and several key questions are reviewed from the perspective of the competing mechanisms of charge transport: the role of each phase in a surface flashover, the origin of surface charging, and effects of traps in solid on surface flashover. Then, some suggestions involve charge transport processes in each phase, and their correlations are put forward, and a predictable ‘charge transport competitive flashover model’ is proposed by clarifying the competing mechanisms of charge transport processes through multiple phases. This study summarises the history and hot topics of physical mechanisms of surface flashover proposed based on classic and recent progress and offers promising routes for developing a more precise surface flashover theory and improving surface flashover performances.

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“…); (3). Solid intrinsic properties (traps [68][69][70][71][72], permittivity [55,[73][74][75], conductivity [76][77][78] etc. );…”

Section: Insufficiencies Of Existing Surface Flashover Modelsmentioning

confidence: 99%

“…Here, we categorised influencing factors into five kinds: Shape of the insulator (geometry [54–56], angle [54, 56–59], discharge gap [17, 60, 61] etc. ); …”

Section: History Of Surface Flashover Modelsmentioning

confidence: 99%

Surface flashover in 50 years: Theoretical models and competing mechanisms

Liu

Ohki

et al. 2023

High Voltage

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“…Increasing voltage systematically was employed to measure the impulse flashover voltage. 14,15 Initially, the samples were subjected to a low impulse voltage (20 kV) and then the peak value was increased by 2 kV at every stage until flashover happened. For each step, the samples underwent three tests.…”

Section: B Experimentsmentioning

confidence: 99%

Enhanced flashover strength in polyethylene nanodielectrics by secondary electron emission modification

Wang

Min

2016

AIP Advances

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This work studies the correlation between secondary electron emission (SEE) characteristics and impulse surface flashover in polyethylene nanodielectrics both theoretically and experimentally, and illustrates the enhancement of flashover voltage in low-density polyethylene (LDPE) through incorporating Al2O3 nanoparticles. SEE characteristics play key roles in surface charging and gas desorption during surface flashover. This work demonstrates that the presence of Al2O3 nanoparticles decreases the SEE coefficient of LDPE and enhances the impact energy at the equilibrium state of surface charging. These changes can be explained by the increase of surface roughness and of surface ionization energy, and the strong interaction between nanoparticles and the polymer dielectric matrix. The surface charge and flashover voltage are calculated according to the secondary electron emission avalanche (SEEA) model, which reveals that the positive surface charges are reduced near the cathode triple point, while the presence of more nanoparticles in high loading samples enhances the gas desorption. Consequently, the surface flashover performance of LDPE/Al2O3 nanodielectrics is improved.

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Beneficial role of manganese dioxide for reducing surface resistivity to increase surface flashover voltage of vacuum insulating ceramics

Li,

Huang,

et al. 2024

Ceramics International

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Improvement of Surface Flashover Performance in Vacuum of A-B-A Insulator by Adopting ZnO Varistor Ceramics as Layer A

Cited by 24 publications

References 13 publications

Surface flashover in 50 years: Theoretical models and competing mechanisms

Surface flashover in 50 years: Theoretical models and competing mechanisms

Enhanced flashover strength in polyethylene nanodielectrics by secondary electron emission modification

Beneficial role of manganese dioxide for reducing surface resistivity to increase surface flashover voltage of vacuum insulating ceramics

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