Investigation of the rotating arc plasma generated in transverse magnetic field (TMF) contacts of vacuum interrupter

The present paper deals with the problem of the TMF interruption systems breaking capability concerning vacuum circuit breakers. The main goal is a better understanding of the physical phenomena taking place during the interruption process, for high currents, corresponding to short-circuit regime in the electrical networks. The arc appearance and its behaviour were explored with a dedicafed optical sqstem. An example of spatial and temporal distribution of the arc light intensity is presented. Specific peculiarities of the optical spectra recorded in the proximi@ of the short circuit current zero (C.Z.) moments are reported. Different current interruption situations are correlated with plasma spectral diagnosis. On this basis the authors try to define a set of plasma parameters which are critical in the studied interruption processes.