Abstract: The present disclosure relates to a bidirectional semiconductor circuit breaker including a primary circuit unit connected between a power supply and a load and in which a first semiconductor switch and a second semiconductor switch are arranged in series and a snubber circuit unit of which one end is connected to the front end of the first semiconductor switch and the other end is connected to the rear end of the second semiconductor switch, in parallel. The snubber circuit unit includes a first circuit line, a second circuit line, and a third circuit line of which one end and the other end are connected to the first circuit line and the second circuit line, respectively, and in which a first resistor and a second resistor are arranged in series, and provide a snubber circuit which is applicable to a bidirectional fault current and satisfies semiconductor protection and current restraining performance.

Abstract: The present disclosure provides an inverter control device for estimating the magnetic flux of a rotor, and calculating and compensating for a slip frequency on the basis of a torque current and a magnetic flux current, to control the speed of an electric motor. To this end, the present invention may comprise: a command voltage generation unit for outputting a three-phase PWM voltage with respect to a command frequency to an inverter on the basis of voltage/frequency operation; and a slip frequency determination unit for determining a slip frequency on the basis of the phase current and phase voltage of an electric motor driven by the inverter.

Abstract: An apparatus for retracting and extending a main body of a circuit breaker includes: a conveying module for retracting or extending the main body into or from a distribution box of the circuit breaker; a lever module including a lever selectively switching between a first state and a second state, where the lever module allows movement of the conveying module when the lever is in the first state, and disallows movement of the conveying module when the lever is in the second state; and an interlock module configured to allow the lever to switch to the first state only when a predetermined external input is applied to the interlock module.

Abstract: The present specification relates to an uninterruptible power supply device, an uninterruptible power supply system and a method for controlling the uninterruptible power supply system, and relates to a power supply device comprising a circuit breaker for switching connection to a power bus, thereby controlling the reception and supply of the power by opening and closing the circuit breaker according to various situations occurring in a system, a power supply system and a method for controlling the power supply system.

Abstract: The present specification relates to a power supply system enabling uninterruptible power supply, the system including a circuit breaker for regulating respective converters to which a plurality of power supply devices are connected, so as to control a power supply and demand by the opening and closing of the circuit breaker according to various situations occurring in the system, thereby enabling a UPS function to be performed between the plurality of power supply devices.

Abstract: The present disclosure provides an inverter control device which estimates back electromotive force of an induction motor, and which uses a torque current and a flux current so as to calculate a slip frequency and compensate for same, thereby enabling the motor to operate at a constant speed. To this end, the present invention may comprise: a command voltage generating unit for outputting, to an inverter, a three phase PWM voltage with respect to a command frequency on the basis of a voltage/frequency operation; and a slip frequency determining unit for determining a slip frequency on the basis of a phase current and a phase voltage of a motor driven by the inverter.

Abstract: The present disclosure relates to an earth leakage circuit breaker and a method for controlling the same. The earth leakage breaker includes a zero-phase current detection unit for detecting a zero-phase current generated in a zero current transformer formed in three-phase electrical lines; a voltage detection unit for detecting a voltage from each of the two electrical lines; a trip unit for tripping contact points between the two electrical lines and a single-phase load when a trip signal is inputted; and a control unit which, when the zero-phase current is detected by the zero-phase current detection unit, detects an electrical line in which the voltage has dropped by a predetermined level or more, and generates and outputs the trip signal to the trip unit when the electrical line in which the voltage has dropped by a predetermined level or more exists.

Abstract: The present disclosure relates to a high speed earthing switch of a gas insulated switchgear and, more specifically, to a high speed earthing switch of a gas insulated switchgear, which includes an air blower so as to secure an improved arc interruption performance. A high speed earthing switch of a gas insulated switchgear according to an embodiment of the present disclosure comprises: an outer case; a cylinder member installed inside the outer case and having a ventilation hole formed along the lower circumferential surface; and a piston member installed to be inserted into the cylinder member, and moving backward and forward by means of a force transferred from a driving unit so as to inject air inside the cylinder member to a contact part when the cylinder member is opened.

Abstract: The present device was conceived in order to resolve the aforementioned problem, and the objective thereof is to provide an arc chamber of a circuit breaker that enhances assemblability and ensures the consistency of the product. An arc chamber of the circuit breaker according to one embodiment of the present device comprises: a plurality of grids arranged at predetermined intervals outside a motion locus of a movable contactor and having a body portion and a leg portion extending from one side of the body portion; and a fixing cap having a receiving portion that is inserted into the leg portion in a press-fitting manner, wherein the fixing cap has a coupling portion extending to a side of the body portion at one side thereof.

Abstract: A power supply apparatus includes a plurality of power modules for receiving alternating current power to provide the power to a load; an uninterruptible supply module to supply self-power to the load; an inverter module installed on one side of the power modules or the uninterruptible supply module to convert the power and provide converted power to the load; direct current bus bars provided inside enclosures of the power modules, the uninterruptible supply module, and the inverter module, respectively; and a connection bus bar for connecting adjacent direct current bus bars, wherein in the power modules and the uninterruptible supply module, an alternating current/direct current converter or a direct current/direct current converter is provided in the upper portion of the direct current bus bar, or the alternating current/direct current converter or the direct current/direct current converter is provided in the lower portion of the direct current bus bar.

Abstract: A DC circuit breaker according to various embodiments may comprise: a first terminal unit connected to a power source; and a second terminal unit connected to the first terminal unit and connected to a load, wherein the first terminal unit includes at least a pair of first terminals connected to each other in parallel and connected to the power source, and the second terminal unit includes at least a pair of second terminals corresponding respectively to the first terminals and connected to each other in parallel so as to be connected to the load.

Abstract: This disclosure relates to a hierarchical power control system linked to a cloud server comprising a first microgrid cell including a first ESS equipped with a UPS structure and a first load with a power state managed by the first ESS; a second microgrid cell including a second load and a second ESS that manages a power state of the second load; a third microgrid cell including a third load; an emergency cell including an additional ESS equipped with a UPS structure and an additional emergency generator, and selectively connected to the second microgrid cell; a middleware server which communicates with the first to third microgrid cells and the emergency cell; and an integrated control system for receiving power supply state information of the first to third microgrid cells, and establishing an integrated operation schedule based on the received power supply state information of the first to third microgrid cells.

Abstract: A current sensing device according to the present invention may comprise: a substrate part which includes at least two base substrates stacked in one direction and through which a circuit passes in the one direction; a coil part which is formed on at least one of the base substrates and surrounds the circuit; and a core part which is disposed between the base substrates while being spaced apart from the coil part, and surrounds the circuit.

Abstract: The present disclosure relates to a modular current limiting resistor comprising a plurality of plate resistors, wherein the plate resistors each comprise a pair of coupling pieces and a conducting line integrally formed with the coupling pieces and having a zigzag shape between the coupling pieces; a pair of support frames which support the stacked plate resistors; a plurality of coupling members which pass through one of the support frames, pass the coupling pieces, and are inserted into the plate resistors; a plurality of conductor rings disposed between the plate resistors while passing through and being inserted into the coupling members, and which electrically connect the conducting line on each of the plate resistors; and at least one unit module comprising a plurality of insulating rings disposed between the plate resistors while passing through and being inserted into the coupling members so as to insulate the plate resistors.

Abstract: A high voltage electric switchboard in which manufacturing productivity is greatly improved and each functional part can be easily replaced and repaired is provided. In the high voltage electric switchboard, a plurality of functional parts including a bus bar part, a measurement and supervisory controller, a circuit breaker part, a wire part, and potential transformer part are independently modularized such that the functional parts do not have a shared surface with each other and at least two outer surfaces of an enclosure of each of the modularized functional parts are installed to be in contact with an outer surface of an enclosure of another functional part adjacent in a horizontal direction or a vertical direction.

Abstract: A photovoltaic system and a control method therefor are disclosed. A photovoltaic system according to an embodiment of the present disclosure comprises: a solar cell array for converting solar energy into electric power; a power management device for monitoring the power generation amount of the solar cell array and the reverse power from an external power grid; an energy storage device charged by receiving the electric power produced by the solar cell array or the power of the external power grid; and a power control device for supplying, to the energy storage device, the electric power generated by the solar cell array or the power of the external power grid in response to a valid power command, wherein the power management device generates the valid power command which has different values according to whether the reverse power is generated by the external power grid.

Abstract: The earth leakage circuit breaker of the present disclosure includes a leakage current detection unit outputting a leakage current detection signal; a conversion unit outputting the leakage current magnitude of a fundamental wave component, a ratio of a third harmonic component, and a ratio of a positive pole peak current value to a negative pole peak current value; and a control unit comparing the leakage current magnitude of a fundamental wave component, the ratio of a third harmonic component, and the ratio of a positive pole peak current value to a negative pole peak current value with predetermined reference values to determine whether a leakage current of the alternating current component is generated or a leakage current of the direct current component is generated and to thereby output a trip control signal when it is determined that the leakage current of the direct current or alternating current component is generated.

Abstract: The present disclosure relates to a thermal image monitoring apparatus and a distributing panel having the same. According to the present disclosure, a rotation-vibration reduction unit and a horizontal vibration reduction unit can prevent relative sliding between a base and a bracket and between the bracket and a thermal image camera, and also reduce vibration in a rotating direction or one direction by virtue of contact with each other.

Abstract: The present disclosure relates to an arc extinguishing unit of a molded case circuit breaker with a barrier provided between a fixed contact and a movable contact when a circuit is cut off, including fixed contacts fixed to part of a base assembly case; movable contacts that come contact or are separated from the fixed contacts; and an arc extinguishing part that extinguishes an arc generated when the movable contacts are separated from the fixed contacts. The arc extinguishing part includes a pair of side plates; multiple grids installed at a fixed interval between the pair of side plates; and arc barriers each installed on a base assembly case in a slidable manner, and configured to be in an open state of being separated from the movable contacts when a normal current flows on the circuit or is cutoff, and to close when a fault current is cutoff.