Abstract: Embodiments of a synthetic test circuit for a valve performance test of high-voltage direct current (HVDC) are presented. In some embodiments, the synthetic test circuit comprises a resonance circuit configured to comprise a first test valve to test an operation of an inverter mode and a second test valve to test an operation of a rectifier mode. The synthetic test circuit may comprise a power supply (P/S) configured to provide the resonance circuit with an operating voltage. The synthetic test circuit may comprise a direct current/direct current (DC/DC) converter configured to bypass a DC offset current of the resonance circuit. The first test valve may be an inverter unit, which may have a positive DC current offset. Further, the second test valve may be a rectifier unit, which may have a negative DC current offset.

Abstract: Disclosed is a system for controlling a water turbine generator for waterworks, which monitors and controls a plurality of water turbine generators, provided in a water pipe, for waterworks in real time to integratedly operate the water turbine generators, contributes to stably generate and secure power, and increases an efficiency of the water turbine generators through integrated management.

Abstract: Disclosed is a message processing unit provided in a PLC system including a master and a plurality of slaves. The message processing unit is provided to each of the slaves and includes a first filter configured to receive a message transmitted from the master and to determine whether the message is a broadcast message, a second filter configured to receive the message delivered from the first filter and to determine whether the message is a message-to-be-processed, and a processor configured to process the message he delivered from the first filter or the second filter.

Abstract: According to an embodiment, a method of controlling an inverter including a rectification unit rectifying inputted AC power to DC power, a smoothing unit smoothing the DC power, and a power conversion unit received the DC power from the smoothing unit to convert the received DC power into AC power having a predetermined size and frequency, the method includes receiving an abnormal signal of the inverter or an electric motor for driving the inverter, determining whether a DC terminal voltage of the smoothing unit is equal to or greater than a low voltage failure level when the abnormal signal is received, determining whether the power conversion unit is operating, and blocking current output of the power conversion unit when the DC terminal voltage is equal to or greater than the low voltage failure level and the power conversion unit is operating.

Abstract: Embodiments of an electric power measuring system capable of computing accurate electric power information using a low voltage measuring instrument in a small-scale electric power system are provided. The electric power measuring system may include a first measuring instrument for measuring and detecting a current and a zero-cross point from a distribution line and for generating and outputting current information of the distribution line from the current and the zero-cross point, and a second measuring instrument for computing electric power information of the distribution line according to a voltage thereof and the current information output from the first measuring instrument.

Abstract: A device for controlling a high voltage direct current (HVDC) transmission system is provided. The device includes: a communication unit communicating with a control device; a control unit obtaining a databack signal received through the communication unit, checking a data line error and a line connection error based on an obtained databack signal, and outputting a valve control signal based on the databack signal; and an output unit outputting the valve control signal to a valve control device based on control of the control unit.

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: Disclosed are a single-phase photovoltaic inverter and a control method thereof in which a small insulated transformer and an ordinary current transformer are used to measure a leakage current instead of a high-priced current transformer that is only used to measure a leakage current. The single-phase photovoltaic inverter that converts DC electric power supplied from a single-phase photovoltaic module into AC electric power includes an input terminal including a first input terminal connecting to a positive polarity of the single-phase photovoltaic module and a second input terminal connecting to a negative polarity of the single-phase photovoltaic module, an inverter unit configured to convert DC electric power supplied through the input terminal into AC electric power and supply the converted AC electric power to a grid, and a leakage current measuring unit connected in parallel with the inverter unit and configured to measure a leakage current delivered through the input terminal.

Abstract: An interconnection evaluation system according to the present disclosure includes a switchboard including at least one endpoint, at least one endpoint contact tester configured to transmit a digital input signal obtained from each endpoint, an automation tester configured to output a preset digital output signal to the switchboard, and to generate interconnection information at each endpoint by reflecting the digital output signal and digital input signal, and an interface unit configured to generate a switchboard status information of switchboard by reflecting the interconnection information.

Abstract: An interlock apparatus of a ring main unit is provided. The interlock apparatus of the ring main unit may change a rotational motion of the shaft included in the circuit breaker to a rectilinear motion, and thus, the insertion hole may be opened or closed according to a closed or cutoff state of the circuit breaker. Accordingly, in the closed state of the circuit breaker, the control of a state of the disconnector is prevented.

Abstract: A deviation compensation method of a potential transformer is provided. The deviation compensation method includes: providing first to Nth potential transformers to be installed at different locations in a high voltage direct current (HVDC) transmission system; supplying a first voltage to the first to Nth potential transformers provided; measuring voltage values output through the first to Nth transformers by the first voltage supplied; determining whether there is a deviation between the measured voltage values; and determining compensation values for correcting the measured voltage values to the same voltage value when there is the deviation.

Abstract: Disclosed is an event input module, wherein the event input module receives time information which is an IRIG-B signal of a predetermined method from an outside time provider, allocates the time information to a detected event and determines event generation information.

Abstract: A method for controlling temperature of an inverter system having an inverter and a cooling fan is provided, the method including: obtaining an internal temperature of the inverter and a DC (Direct Current)-link voltage of the inverter; and outputting a fan driving control signal for driving the fan or maintaining the fan being driven to the fan, when the internal temperature is above a predetermined fan drive setting temperature and the DC-link voltage is above a predetermined fan drive setting voltage.

Abstract: Disclosed are a three-phase wiring detection device and a coincidence phase detection method. The three-phase wiring detection device and the coincidence phase detection method compare a power factor relationship between a three-phase voltage and a three-phase current, and determines whether a coincidence phase is coincident between the three-phase voltage and the three-phase current, thereby checking whether the coincidence phase is accurately coincident. Therefore, whether the coincidence phase is coincident between the three-phase voltage and the three-phase current can be checked, and a function of a reverse phase detector and a function of a coincidence phase checker can be implemented. Also, the three-phase voltage and the three-phase current can be accurately detected.

Abstract: An energy storage system including a plurality of loads each converting direct current (DC) power stored in a battery thereof into alternating current (AC) power and outputting the AC power, a plurality of slave power controllers detecting zero crossing points of AC voltage signals output from one of the plurality of loads and controlling the plurality of loads in accordance with a control signal received from a master power controller, and the master power controller controlling the plurality of slave power controllers so as to control the plurality of loads in accordance with the control signal received from the master power controller after a preset time has lapsed since the detected zero crossing point.

Abstract: Provided is a molded case circuit breaker eliminating the necessity to install a communication unit and a particular communication medium and allowing for checking an fault type from a front indication operation panel of an enclosure of a power distributing board or from a remote area by simply connecting two signal lines for transmitting a relay switching signal as an accident current indication signal, the circuit breaker comprises a relay assembly including a plurality of fault indicating relays installed in the circuit breaker and configured to generate a fault current indication signal by opening or closing a contact when the indication command signal of a fault current is received from the electronic trip unit, and a signal output terminal configured to output a fault type indication signal of the fault indicating relays to the outside of the circuit breaker.

Abstract: In some embodiments, a system for driving inverters in parallel includes a master controller, a plurality of slave controllers, and a plurality of inverters controlled correspondingly by each of the slave controllers. The system may further include a control signal creation unit to create control signals for the slave controllers by using data transmitted and received between the master controller and the slave controllers to enable the plurality of inverters to create balanced output currents.

Abstract: Integrated circuits described herein implement an x-input logic gate. The integrated circuit includes a plurality of Schottky diodes that includes x Schottky diodes and a plurality of source-follower transistors that includes x source-follower transistors. Each respective source-follower transistor of the plurality of source-follower transistors includes a respective gate node that is coupled to a respective Schottky diode. A first source-follower transistor of the plurality of source-follower transistors is connected serially to a second source-follower transistor of the plurality of source-follower transistors.

Abstract: A security apparatus for an energy storage system is provided. The security apparatus includes a sensor input unit receiving security state information including door opening and closing and locking/unlocking from a door opening and closing sensor and a locking/unlocking sensor; a human machine interface (HMI) unit receiving information from a user or showing the information to the user; and a security state machine allowing manipulation of the energy storage system depending on whether security state information obtained through the sensor input unit satisfies a security state condition having a plurality of procedures in order.

Abstract: A converter and an operation method thereof are provided. A converter interconnected with a wind power generation farm includes a power monitor unit configured to detect a direct-current voltage of an entire system interconnected with the converter, a control unit configured to compare the detected direct-current voltage of the entire system with a reference voltage and adjust an alternating-current voltage that is supplied to the wind power generation farm to a preset value, and a switching unit configured to perform a switching operation based on the adjusted preset value to convert alternating-current power into direct-current power.