DC BREAKER

摘要

The purpose of the invention is to obtain a DC breaker capable of separating an accident point at a higher speed and capable of being reduced in size and cost. The DC breaker comprises: a bridge circuit (6) configured by connecting, in an inverse parallel fashion, two series circuits (6a, 6b) each consisting of a reactor (2) and a commutation unit (3) including a capacitor (5); a first breaker unit (1) connected between the connection points between the reactor (2) and the commutation unit (3) both included in each of the series circuits (6a, 6b), being in a closed state at a normal time when a constant current flows in a DC line, controlled to be opened after an accident occurs at the DC line, and interrupting at a current zero point in which the current flowing through each reactor (2) and the current flowing through each commutation unit (3) are cancelled with each other; and a second breaker unit (4) connected to the bridge circuit (6) in series, being in the closed state at the normal time, controlled to be opened after the first breaker unit (1) interrupts, and interrupting at a current zero point in which the currents flowing through the respective series circuits (6a, 6b) are canceled with each other.