Characteristics of Field-Emission-Induced Breakdown With Conical Microprotrusion

Microprotrusions on plane electrode surface of vacuum interrupter are the main cause of field-emission-induced breakdown. The microprotrusions are difficult to observe because of the ceramic insulations and floating shield, and they will be destroyed by breakdown events. This article aims to reveal the characteristics of field-emission-induced breakdown with conical microprotrusion. The conical microprotrusions are reconstructed based on Fowler–Nordheim theory with field-emission current and applied voltage from breakdown experiment. The conical microprotrusions temperature characteristics are obtained with Joule heating effect taking into consideration, which could help to confirm the validity of the reconstructed microprotrusions. The relationship between conical microprotrusions geometrical parameters and field-emission characteristics is analyzed. The results would clarify the effects of conical microprotrusion on plane electrode surface on field-emission-induced breakdown.