143 / 2024-04-14 22:22:54

The Impact of a Targeted Current Conditioning Method on the Short-Circuit Current Breaking Capacity of Vacuum Interrupters with Plane Electrodes

vacuum interrupter, plane electrode, high current breaking, conditioning, target current

Abstract: The prevailing consensus regarding the efficacy of vacuum interrupters in breaking high currents is that it predominantly depends on optimizing the magnetic field within the electrode gap to facilitate arc diffusion. Improving the arc-controlled magnetic field, which includes transverse and longitudinal magnetism, often requires optimization of the electrode structure. However, such a structure, such as the spiral grooved structure, will impact electric field distribution across the electrode surface, contact resistance, and mechanical strength of the electrodes, among other properties. As a result, this limits improvements in the vacuum interrupter’s performance in terms of insulation, current conduction, and interruption. In this study, a targeted current conditioning method was employed to treat a vacuum interrupter with plane electrodes. This method involves using a high-voltage pulse of low energy to break down the electrode gap, achieving precise localization of the insulation weak spot on the electrode surface. Subsequently, high currents are directed to treat the spot. The experiment utilized a 12-kV vacuum interrupter featuring a circular plane electrode made of CuCr50, with a diameter of 45 mm. Results from the conditioning and short-circuit current interruption experiments indicate that, after undergoing the targeted conditioning treatment, the vacuum interrupter can reliably break short-circuit currents of up to 31.5 kA, significantly surpassing the breaking capacity of traditional planar electrodes. These findings provide new ideas for improving vacuum breaking capacity.