Reignition phenomena after high-frequency current interruption with short vacuum gaps

Based on a large number of measurements of high-frequency (HF) current inte rruptions in vacuum at small contact gaps (< 600 mu m), the statistical rei gnition behavior of vacuum switching devices after a HF current zero is inv estigated. Three types of reignitions can he classified, Statistical evalua tion of post-arc current measurements for different parameters at current z ero and different HF current ignition processes gives information about the stress of the gap as a result of the transient recovery voltage after a HF current zero (HF-TRV) and the accumulated post-are charge. Comparing post- are current values at the beginning of the HF-TRV and at the moment of reig nition reveals a production of charge carriers during the recovery interval , Possible reasons for the different types of reignitions are discussed.