Abstract: A direct-current circuit includes: a breaker that is inserted into the direct-current line and becomes a path for direct current when in a steady state; a resonance circuit connected in parallel with the breaker and superimposing resonance current on the direct current; and a first disconnector and a second disconnector connected to first and second connection points of the breaker and the resonance circuit, respectively, and forming a path for the direct current together with the breaker. The resonance circuit includes a series circuit that includes a capacitor and a reactor and generates the resonance current, a charging resistor for charging the capacitor with a direct-current potential of the direct-current line, a high-speed switch connected in series with the series circuit on the capacitor side and superimposing the resonance current on the direct current, and an arrester connected in parallel with the capacitor and the high-speed switch.

Abstract: A direct-current circuit includes: a breaker that is inserted into the direct-current line and becomes a path for direct current when in a steady state; a resonance circuit connected in parallel with the breaker and superimposing resonance current on the direct current; and a first disconnector and a second disconnector connected to first and second connection points of the breaker and the resonance circuit, respectively, and forming a path for the direct current together with the breaker. The resonance circuit includes a series circuit that includes a capacitor and a reactor and generates the resonance current, a charging resistor for charging the capacitor with a direct-current potential of the direct-current line, a high-speed switch connected in series with the series circuit on the capacitor side and superimposing the resonance current on the direct current, and an arrester connected in parallel with the capacitor and the high-speed switch.