Abstract: A high-voltage DC circuit breaker for breaking a current that flows in a DC line, including: a main switch, installed on the DC line, for breaking a current of the DC line by opening when a fault occurs on one side or a remaining side of the DC line; a nonlinear resistor connected in parallel with the main switch; an LC circuit that is connected in parallel with the main switch and includes a capacitor and a reactor, which are connected in series in order to generate LC resonance; a first bidirectional switching element, connected to the LC circuit in series, for switching a bidirectional current flow; and a second bidirectional switching element, connected in parallel with the LC circuit, for switching a current flow to induce LC resonance in both directions.

Abstract: The present invention relates to a modular apparatus for a high-voltage direct-current transmission system. A sub-module (10), which is a modular apparatus, comprises according to the present invention a power unit (12) in the front and a capacitor unit (13) in the rear, and on the lower end of a front surface (14?) of a power unit housing (14) forming the exterior of the power unit (12) is a sloped surface (15). The sloped surface (15) has a hexahederal shape created by removing the edge formed by the front surface (14?) and the bottom surface of the power unit housing (14) and faces the ground at an angle. A display unit (16) is provided on the sloped surface (15) so that the status of the sub-module (10) can be easily checked by a worker from the ground on which a structure stands.

Abstract: The present invention relates to a module extraction apparatus of a high voltage direct current system. In the present invention, a fixed base (30) is secured to a structure (82), and a sub-module (10) is mounted on a movable base (60) that slides on the fixed base (30), thereby enabling the sub-module (10) to be extracted from the structure (82). The sub-module (10) may be separated into a power unit (12) and a capacitor unit (24) which may be separately extracted from the structure (82). A connection support (84) is connected to the fixed base (30) and installed to protrude toward the outside of the structure (82), and the tip end of the connection support (84) extending toward the outside of the structure (82) is supported by a wire (86). As described above, the present invention has an advantage of more easily extracting the module, which is a heavy object, from the structure (82) to carry out the maintenance thereof.