Investigation of the rotating arc plasma generated in a vacuum circuit breaker

The main goal of this work is a better understanding of the physical phenomena taking place during the high currents interruption process, corresponding to short-circuit regime in the electrical networks. The arc appearance and its behavior in vacuum circuit breakers with cup-shaped electrodes were explored with an adequate optical system. Different current interruption situations were correlated with optical plasma diagnosis. Specific peculiarities of the time resolved spectra recorded in the proximity of the short circuit current zero (c.z.) moments are reported. On this basis the authors attempt to define a set of plasma parameters which are critical for the studied interruption processes and the breaking capability evaluation.