US 12,243,697 B2
Direct-current circuit breaker and direct-current circuit breaker system
Takashi Inagaki, Tokyo (JP); and Sho Tokoyoda, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 18/247,304
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Dec. 9, 2020, PCT No. PCT/JP2020/045906
§ 371(c)(1), (2) Date Mar. 30, 2023,
PCT Pub. No. WO2022/123700, PCT Pub. Date Jun. 16, 2022.
Prior Publication US 2023/0411091 A1, Dec. 21, 2023
Int. Cl. H01H 33/59 (2006.01); H02H 3/087 (2006.01); H01H 9/54 (2006.01)
CPC H01H 33/596 (2013.01) [H02H 3/087 (2013.01); H01H 9/542 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A direct-current circuit breaker comprising:
an interrupter inserted in a direct-current line, the interrupter being closed in a steady state;
a resonance circuit connected in parallel to the interrupter, the resonance circuit including a capacitor, a reactor, and a first switch connected in series with each other, the first switch being open in a steady state;
a voltage detection circuit adapted to detect a charging voltage of the capacitor;
a charging circuit adapted to charge the capacitor at a direct-current potential of the direct-current line, the charging circuit including a charging resistor and a second switch connected in series, the charging resistor being grounded; and
a control circuit adapted to interrupt a direct current flowing through the direct-current line when an accident occurs, by closing the first switch, superimposing a resonance current generated by the resonance circuit on the direct current to create a current zero point, and opening the interrupter, wherein
the control circuit is adapted to:
close the second switch to charge the capacitor;
thereafter, open the second switch when the charging voltage having been detected exceeds a first voltage value; and
close the second switch when the charging voltage having been detected falls below a second voltage value that is smaller than the first voltage value.