Patent ID: 9450394
Filing Date: 2016-09-20
CPC Classification: H01H,H02H

Claim Text:
1. A method for switching off a high-voltage DC current from a voltage source delivering a nominal voltage by means of a circuit breaker including a semiconductor switching assembly and at least one mechanical switch in series, wherein the semiconductor switching assembly includes a plurality of semiconductor switches and a plurality of arresters in parallel to the semiconductor switches, the method comprising: switching off the semiconductor switching assembly to reduce current in the circuit breaker to a residual current; and switching off the residual current by means of the mechanical switch, wherein: the arresters have an added threshold voltage exceeding the nominal voltage; the mechanical switch is arranged in a resonant circuit configured to generate an oscillating current through an arc in the mechanical switch after switching off the semiconductor switching assembly and opening the mechanical switch; the oscillating current has an amplitude exceeding the residual current such that at least one current zero crossing can be generated in the arc of the mechanical switch; and the method comprises extinguishing the arc during the current zero crossing.