Abstract: A method for measuring electric power value in a HVDC system comprises the steps of receiving current values and voltage values, which are measured from sensor group installed in specific positions of an electric power conversion station; identifying a line impedance of the positions where the sensor group are installed; calculating a first electric power value of the electric power conversion station; calculating a second electric power value of the electric power conversion station; calculating a third electric power value of the electric power conversion station; and determining one of the second and third electric power values as an actual electric power value of the electric power conversion station by comparing the calculated first to third electric power values with one another.

Abstract: A data collection device for photovoltaic power generation is provided. The data collection device for collecting photovoltaic power generation data includes a reception unit receiving, from a photovoltaic device, generation that absorbed solar energy is converted into electrical energy, and photovoltaic power generation related information; a storage unit storing the photovoltaic power generation related information on the photovoltaic device; a control unit determining a predicted life of the photovoltaic device based on the photovoltaic power generation related information received from the reception unit and accumulated related information stored in the storage unit; and a transceiver transmitting a result of determination to an external device.

Abstract: An charging control device includes: one or more slave groups including a plurality of slaves for charging or discharging a battery; and a master configured to transmit, to the one or more slave groups, a control signal for controlling operations of the one or more slave groups, and select one of a plurality of slaves included in each of the one or more slave groups as an alternative master, wherein the alternative master is a slave capable of performing some or all of all functions of the master.

Abstract: A method for measuring electric power loss of a high voltage direct current (HVDC) system comprises the steps of measuring the amount of transmission electric power and the amount of receiving electric power; calculating a first electric power loss amount based on a difference value between the measured amount of the transmission electric power and the measured amount of the receiving electric power; calculating the amount of loss generated in each of positions in the HVDC system based on an impedance value of each of the positions; calculating a second electric power loss amount based on a sum value of the calculated loss amounts; and determining a correcting value for correcting the amount of electric power loss generated in the HVDC system based on a difference value between the first electric power loss amount and the second electric power loss amount.

Abstract: The present disclosure relates to provide an active erroneous sample elimination device or erroneous sample elimination method for a relay capable of correctly implementing erroneous sample elimination processing even during a plurality of electrical disturbances mixed with an electrical quantity detection signal, and a digital protective relay according to the present disclosure may include a converter that samples an analog signal and converts the sampled signal to a digital signal; and a processor that searches an inflection point at which an electrical variation quantity varies from an increase to a decrease or from a decrease to an increase based on the digital signal, and compares an electrical variation quantity prior to and subsequent to the inflection point with a preset electrical quantity.

Abstract: A power supply system includes: an electricity generation device configured to generate electrical energy; a plurality of DC/AC converters configured to convert the electrical energy into AC; and a battery energy storage system (BESS) configured to receive and charge the electrical energy and supplies the electrical energy to the plurality of DC/AC converters by discharging the charged electrical energy. The electrical energy generated by the electricity generation device charges the BESS without going through the plurality of DC/AC converters.

Abstract: Provided is a Battery Energy Storage System (BESS) management device for managing a BESS for receiving and charging electrical energy and supplying the electrical energy to a DC/AC converter by discharging the charged electrical energy in a power supply system. The BESS management device includes a measurement unit configured to measure State of Charges (SOCs) of a plurality of series-connected modules or cells in the BESS and a DC power supply unit configured to supply DC power to one of the plurality of modules or one of the plurality of cells on the basis of the SOCs of the plurality of modules or cells.

Abstract: Disclosed are a control unit for a circuit breaker capable of controlling and monitoring various types of switches such as a circuit breaker and a switchgear included in power system equipment, by being attached to the switches or by being implemented in the form of an independent module, and a controlling method thereof. The control unit for a circuit breaker, which interworks with a relay and a circuit breaker, includes: an Ethernet drive configured to receive a GOOSE message type control signal from the relay connected thereto through Ethernet communication; a control module configured to operate the circuit breaker based on the GOOSE message type control signal; and a main control unit (MCU) module configured to transmit the GOOSE message type control signal to the control module, if the received GOOSE message type control signal is related to the control unit.

Abstract: A driving device of a synchronous rectification apparatus is provided. The driving device includes a voltage detection part disposed on a power input terminal to detect a voltage value of a power inputted through the power input terminal, an adjustment part receiving the voltage value detected through the voltage detection part, the adjustment part adjusting the receive voltage value to output the adjusted voltage value, and a comparison part receiving the voltage value adjusted through the adjustment part into a positive terminal and a synchronous rectification starting value into a negative terminal, the comparison part outputting an command value of the synchronous rectification apparatus, which is obtained by comparing the received voltage value with the synchronous rectification starting value.

Abstract: An inverter is provided. The inverter includes a current providing unit providing a first axis current and a second axis current to an induction motor; a revolutions per minute (RPM) measuring unit measuring the RPM of the induction motor; and a control unit changing the second axis current according to the measured RPM.

Abstract: An EtherCAT-based network system configured to change a PDO list set, and an operation method thereof are provided, the system including at least one or more slave devices, a master device configured to connect and operate the slave device in response to an operating transmission PDO list or an operating reception PDO list provided from outside, and a host computer configured to extract the operating transmission PDO list or the operating reception PDO list from information file of the slave device and provide to the master device, wherein the information file includes at least one of identity information of the slave device, PDO list item changeable information, at least one or more transmission PDO list, and at least one or more reception PDO list.

Abstract: Disclosed is an event communication apparatus for a protection relay, which effectively simplifies an event determination operation by a main processing module and a communication module, thereby enhancing updating. The event communication apparatus for the protection relay includes a shared memory configured to store and provide data needed to share, a main processing module configured to, whenever an event occurs, update previous event data to a status information of the event and a status occurrence time information as new event data, and write the updated event data into the shared memory, and a communication module configured to periodically read status information from the shared memory, compare the read status information with pre-stored previous status information to determine whether there is a status change, determine occurrence of a new event when there is the status change, and transmit corresponding event data to an supervisory monitor immediately when the new event occurs.

Abstract: A data collection device for photovoltaic power generation is provided. The data collection device according to an embodiment includes a receiver that receives data on an amount of photovoltaic power generation, a storage unit that stores a representative pattern of a graph for monitoring the amount of photovoltaic power generation, a control unit that extracts a graph for a first piece of data on the amount of photovoltaic power generation received by the receiver and compares the extracted graph with the representative pattern stored in the storage unit to extract a pattern comparison value, and a transmitter that transmits the first piece of data compared by the system control unit to an external device.

Abstract: A sensor-less vector control apparatus for induction motor enhanced in performance of sensor-less vector control by estimating changes in parameters in real time is provided, the apparatus including a current controller, a first phase converting unit, a second phase converting unit, a rotor speed and position estimator configured to measure a rotor speed of a rotor and a rotor flux using an output value of the first phase converting unit and to estimate a rotor position using the output value, and a stator resistance and angle error estimator configured to calculate a stator resistance and an angle error of the induction motor by receiving d, q axis current commands on the synchronous reference frame inputted from the current controller and d, q voltages on the synchronous reference frame outputted from the current controller, and to provide the stator resistance to the rotor speed and position estimator.

Abstract: A terminal circuit in an inverter is disclosed, the terminal circuit including a photo-coupler configured to electrically insulate input/output signals, to receive, as input, an open collector output signal or a pulse output signal from a first port and to output the open collector output signal or the pulse output signal to a second port through a first output terminal, a transistor in which a base (B) terminal is connected to a second output terminal of the photo-coupler. And a bias resistor connected to a base (B) terminal of the transistor and to an emitter (E) terminal.

Abstract: A circuit breaker includes: a main body housing circuit-breaking parts; a terminal portion exposed outside the main body; a lug-type terminal block attached to the terminal portion and connecting a wire to the terminal portion; and an insulating member provided between the lug-type terminal block and the main body.

Abstract: A method for initializing expended modules in PLC (Programmable Logic Controller) system is provided in which an initialization request signal is generated and transmitted to a plurality of expended modules, when one basic unit initializes a plurality of expended modules, and an initialization completion signal is sequentially transmitted by the plurality of expended modules, when the initialization is completed, whereby the initialization time can be optimized, the method including performing an initialization operation after generating, by a basic unit, an initialization request signal and transmitting the initialization request signal to a plurality of expended modules, and determining that the initialization operation is completed, when an initialization completion signal is received from the expended modules connected to the basic unit.

Abstract: Disclosed are an apparatus for alarming an inverter status and an apparatus for analyzing a motor status in a mobile terminal. The apparatus for analyzing a motor status in a mobile terminal includes: a first recognition unit configured to recognize vibrations of a motor contacting thereto, and providing the vibrations to a controller; a second recognition unit configured to recognize sound of the motor, and providing the sound to the controller; and the controller configured to analyze a frequency from the vibrations and sound of the motor, to check a change of the vibrations, and thus to obtain an analysis result on a status of the motor.

Abstract: The present invention relates to a molded case circuit breaker, in which a locking member is formed at an inner side of a lever and an anti-rotation member is formed at an upper like. Accordingly, the locking member can be brought into contact with the anti-rotation member even though a handle is rotated to an OFF position even in a fused state between a fixed contactor and a movable contactor, thereby preventing a rotation of the handle to the OFF position.

Abstract: The present disclosure relates to a structure of a crossbar for a manual motor starter, and particularly, to a structure of a crossbar for a manual motor starter in which a function of an auxiliary lever is performed by a crossbar to thus reduce the number of components and an operational error. The structure of a crossbar for a manual motor starter (MMS) including a crossbar connected to an operating mechanism and an auxiliary contact lever operating an auxiliary contact, wherein a pressing unit is formed in the crossbar to operate the auxiliary contact lever upwardly.