Surface flashover in 50 years: Theoretical models and competing mechanisms

Abstract

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.

Integrated modeling of vacuum flashover development: above-surface processes and breakdown threshold analyses

“…In addition, plasma instabilities can happen with radio-frequency source [56]. These processes are summarized in some recent review articles [9,57], and inevitably cause discrepancies to the present model. For now, they cannot be easily implemented into the vacuum flashover voltage calculation, calling for further investigations.…”

“…Flashover in vacuum primarily initiates from the cathode triple junction (CTJ) and forms a discharge channel crossing the insulator. Vacuum flashover commonly appears in pulsed-power devices, particle accelerator, dielectric window, vacuum interrupter, and numerous high voltage insulation systems [5][6][7][8][9]. Flashover threshold evaluation and mitigation are therefore crucial for a range of applications.…”

The mechanisms of enhanced thickness‐dependent DC breakdown strength of EP/MWCNTs nanocomposites

“…Charge transport in polymeric dielectrics is determined by the trapping factor [46]. In dielectrics, physical and chemical defects that deviate from normal configurations cause traps.…”

The mechanism of EP/SiC coating modulated DC flashover characteristics of epoxy composites in SF6/N2 mixtures

“…A plasma discharge path is formed when the generated electrons collide with the gas molecules and produce substantial quantities of positive ions and electrons. At the anode, where the plasma energy is reached, flashover occurs along the gassolid interface [42][43][44][45]. When an appropriate amount of SiC particles is introduced, (figure 5(d)), the surface conductivity and mobility significantly increase (figure 6) owing to the decrease in the shallow trap level and increase in density (figure 5(d)).…”