Abstract: A telecommunications system for a programmable logic controller (PLC) includes: a master module comprising a transmitter and a receiver; one or more slave modules configured to receive signals transmitted from the transmitter and transmit signals to the receiver in response to the transmitted signals; a signal conversion module configured to convert the signals transmitted between the master module and the slave modules into digital signals; a control module configured to control the signal conversion module and to determine whether there is an error in the signals transmitted between the master module and the slave modules based on the digital signals; a display module configured to display a result of the determination by the control module.

Abstract: A protective relaying system and a data collection method thereof capable of enhancing a data collection efficiency and effectiveness is provided. The protective relaying system may include a plurality of protective relaying modules respectively connected to a switch to control the operation of the switch; a server module coupled to one of the plurality of protective relaying modules, and connected to the plurality of protective relaying modules, respectively, to sequentially collect and store data of the plurality of protective relaying modules; and a remote monitoring unit connected to the server module to collectively receive and collect the stored data of the plurality of protective relaying modules from the server module.

Abstract: Methods for temperature drift compensation of a temperature measurement device using a thermocouple are presented. In one embodiment, the temperature drift may be compensated for through reference junction compensation alone using a thermistor for reference junction compensation without providing a separate temperature measurement element. Thereby, precision of a measured temperature may not change despite change in temperature of the surroundings measured by the temperature measurement device, and the manufacturing cost may be effectively reduced.

Abstract: The present disclosure relates to a reactive power compensation system including a reactive power compensation unit for measuring compensate reactive power, an impedance measurement unit for measuring an impedance value of each of a plurality of loads, and a learning control unit for controlling the reactive power compensation unit based on the measured impedance value.

Abstract: Disclosed is a power supply system. A power supply system according to an embodiment includes a system control unit configured to set a first system droop curve for a plurality of batteries and a charging control unit configured to control charging/discharging of the plurality of batteries on the basis of the first system droop curve.

Abstract: A door locking device of a distribution board of an air circuit breaker, including a transmission shaft transmitting power for drawing in and out a circuit breaker body, a shaft link rotatably coupled to one end of the transmission shaft, a link rod having one end rotatably coupled to a portion of the shaft link, a cam plate rotatably coupled to the other end of the link rod and pushing or pulling the circuit breaker boy, and a constraint plate installed in a distribution board door, further includes a pressing part protruding from a portion of the link road, and a hook plate rotatably coupled to a side of the cradle and having one end in contact with the pressing part to receive rotational force and the other end restricting or releasing the constraint plate, wherein the hook plate releases the constraint plate in a disconnection position.

Abstract: Disclosed herein is a photovoltaic inverter that prevents degradation in the efficiency of photovoltaic generation by applying a reverse voltage of a DC voltage stored in a DC link capacitor to a solar cell array. The photovoltaic inverter includes: a DC link capacitor configured to store a DC voltage output from the solar cell array; a power conversion stage configured to generate an AC power by using the DC voltage stored in the DC link capacitor to transmit the generated AC power to a power system; and a controller configured to apply the DC voltage stored in the DC link capacitor to the power conversion stage or apply a reverse voltage of the DC voltage stored in the DC link capacitor to the solar cell array depending on whether a driving value of the solar cell array satisfies a predetermined driving condition.

Abstract: A data collecting device collecting state information of a photovoltaic device is provided. The data collecting device includes a reception unit collecting the state information, and a transmitting unit transmitting the state information according to a state information transmission time based on a state information group including the state information.

Abstract: Disclosed herein is a slave module for monitoring an electric system. The slave module includes: a data transmitting/receiving unit configured to receive request data from the master module and transmit response data to the master module via the serial bus; a data converting unit configured to convert the request data into first digital data and convert second digital data into the request data; a determining unit configured to determine whether the serial bus is in inactive state based on the first digital data and the second digital data; and a data processing unit configured to transmit emergency data to the master module if it is determined that the serial bus is in the inactive state.

Abstract: A circuit breaker includes a circuit breaker main body unit having a main circuit unit forming a circuit line of each phase, a current transformer part having a coil disposed in the circuit line of each phase and a pair of terminals extending from both ends of the coil and selectively connected to an external power source unit, and a safety switching part configured to connect the pair of terminals such that the pair of terminals are not opened, when the power source unit and the pair of terminals are separated.

Abstract: Disclosed herein is a method of controlling data display device. The method includes: loading a monitoring view to initialize it; determining whether to display a tabular view; setting a tabular module if it is determined that the tabular view is to be displayed; displaying the tabular view according to set conditions; and checking whether to perform a view update mode during the displaying the tabular view.

Abstract: A circuit breaker is provided, which includes a cradle having a plurality of cradle terminals, and a breaker main body connected to the cradle and having a plurality of breaker terminals electrically connected to the plurality of cradle terminals, in which each of the plurality of breaker terminals includes a terminal body extended from the breaker main body and protruded toward each of the plurality of cradle terminals, contacts coupled to upper and lower portions of terminal body and disposed in parallel to face each other, and a contact protrusion protruded to a round shape in a direction which the contacts face each other such that, upon connection of the plurality of cradle terminals, the contact protrusion contacts and presses both sides of the connected cradle terminals.

Abstract: The present invention relates to a connecting device for control terminals in a withdrawable type circuit breaker, and more particularly, a connecting device for control terminals in a withdrawable type circuit breaker, capable of automatically connecting or separating control power source terminals for controlling the circuit breaker upon pulling out or inserting a breaker main body.

Abstract: Disclosed is an apparatus for monitoring a leakage current of a transformer-less photovoltaic inverter, which can reduce the risk of a fault in a grid due to a leakage current in a photovoltaic inverter. The apparatus comprises a low pass filter configured to remove a high-frequency noise of a sensed leakage current signal; an average value calculator configured to calculate an average value of an output of the low pass filter; a direct current component remover configured to subtract the average value from the output of the low pass filter; a phase locked loop circuit section configured to calculate a peak value and a phase of a signal from which the direct current component has been removed; and a resistive component leakage current calculator configured to calculate a resistive component value of a leakage current, based on the peak value and the phase calculated.

Abstract: According to an embodiment, a method for compensating instantaneous power failure includes determining whether an input voltage of a plurality of power cells is less than or equal to a first threshold voltage, decreasing, when the input voltage is less than or equal to the first threshold voltage, an output frequency of the inverter, determining whether a voltage of a direct current (DC) link is greater than or equal to a second threshold voltage, and increasing, when the voltage of the DC link is greater than or equal to the second threshold voltage, the output frequency of the inverter. Overvoltage trip may be prevented at the power restoration time and overcurrent trip caused by increase in the slip frequency may be prevented. Thereby, reliability of a medium inverter may be enhanced, and a continuous operation time increased compared to the conventional cases may be ensured.

Abstract: Disclosed is a phase shift transformer for supplying voltage to a plurality of unit power cells in a medium voltage inverter system. The phase shift transformer according to the present invention comprises a first bushing arranged by the side of a tank and connected to a first winding to apply high voltage and a plurality of second bushings arranged on the top of a cover and connected to each of a plurality of second windings to output low voltage, wherein three outputs of the plurality of second bushings can be applied to unit power cells.

Abstract: The present disclosure relates to a remote management system supporting an N-screen function. A remote management system according to one embodiment of the present disclosure includes a graphic editing unit configured to create a first file including a plurality of layers corresponding to resolutions of plurality of devices, and a remote server configured to verify resolution of a remote terminal and an application standard thereof when receiving a monitoring screen provision request from the remote terminal, and to create a second file corresponding to the resolution of the remote terminal and the application standard thereof, thereby providing the second file to the remote terminal. In accordance with the present disclosure, a graphic file capable of displaying the same monitoring screen on a plurality of devices having a variety of resolutions may be created using a single graphic editing tool, thereby dramatically improving convenience of a system management.

Abstract: Disclosed embodiments relate to a system for correcting an error, which can correct the error of a measurement device and a transformer data unit through calibration using an emulator even if the measurement device and the transformer data unit are connected in a random combination. In some embodiments, the system for correcting an error includes a measurement device connected to a secondary output line of a transformer to measure current that is output from the transformer, a transformer data unit configured to determine a usage rate and an overload state through calculation of a load amount for a capacity of the transformer in accordance with the current that is measured by the measurement device, and an emulator connected to the measurement device and the transformer data unit to perform error correction between the measurement device and the transformer data unit through performing calibration at least once.

Abstract: Some embodiments of the present disclosure relate to a direct current circuit breaker capable of shortening a cut-off operation time and reducing a magnitude of a required reverse current. The direct current circuit breaker includes: a main circuit line which is connected between a power supply and a load, the main circuit line includes a main breaker and a first diode connected in parallel; a charging circuit line which is disposed in the rear stage of the main breaker and is connected in parallel to the load, the charging circuit line includes a first capacitor, a reactor and a second diode connected in series; and a switch line including one end connected in parallel to the front stage of the main breaker and the other end connected between the reactor and the second diode, the switch line includes a third diode and a current switch connected in series.

Abstract: The present disclosure relates a reactive power compensation system including a detection unit for acquiring loading state information of a plurality of loads, a reactive power compensation unit for compensating reactive power, and a controller for controlling the reactive power compensation unit to perform flicker compensation or power factor compensation based on a control signal according to the loading state information.