Abstract: Provided is a fiber composite structure including a plurality of twisted fiber bundles, wherein each of the fiber bundles includes a plurality of fiber strands, an adhesive coated on the fiber strands, and a functional particle interposed between the fiber strands. The functional particle includes a material different from that of the fiber strands. The adhesive includes polydopamine.

Abstract: Provided is a polydopamine composite material according to the concept of the present invention, wherein the polydopamine composite material includes a substrate with first nano-protrusions formed on a surface thereof, and a polydopamine layer on the surface of the substrate. The polydopamine layer includes second nano-protrusions protruding in a direction perpendicular to the surface of the substrate.

Abstract: A method of charging a battery by a charging system comprising a master charging circuit and N (N is a natural number) slave charging circuits. The method includes: sourcing a first current to a single-wired bus by the master charging circuit; absorbing (sinking) a second current from the single-wired bus by the N slave charging circuits connected to the single-wired bus; identifying a single-wired bus voltage formed on the single-wired bus at a particular time point by the master charging circuit; and identifying the number of slave charging circuits based on the single-wired bus voltage by the master charging circuit.

Abstract: A clock and data recovery circuit is disclosed herein. The clock and data recovery circuit includes a phase detection unit, a charge pump, a loop filter, a voltage control oscillator, and a frequency detection unit. The voltage control oscillator has oscillation frequency that is variable in response to a frequency adjustment signal, and outputs an oscillation signal. The frequency detection unit includes a reference clock divider, a counter, and an oscillation frequency control unit. The reference clock divider generates a count-enable signal based on a reference clock signal. The counter generates an oscillation count signal by counting the pulses of the oscillation signal of the voltage control oscillator or the pulses of divided signals resulting from dividing the oscillation signal while the count-enable signal is being enabled. The oscillation frequency control unit compares a target count value with the value of the oscillation count signal, and outputs the frequency adjustment signal.

Abstract: A method of charging a battery by a charging system comprising a master charging circuit and N (N is a natural number) slave charging circuits. The method includes: sourcing a first current to a single-wired bus by the master charging circuit; absorbing (sinking) a second current from the single-wired bus by the N slave charging circuits connected to the single-wired bus; identifying a single-wired bus voltage formed on the single-wired bus at a particular time point by the master charging circuit; and identifying the number of slave charging circuits based on the single-wired bus voltage by the master charging circuit.

Abstract: Disclosed herein is an active rectifier. The rectifier includes a rectifier unit, a driver unit, and a switching device control circuit unit. The rectifier unit includes first and fourth transistors configured to become conductive when the voltage of an alternating current (AC) input is negative and apply the current of the AC input to a rectifier capacitor, and second and third transistors configured to become conductive when the voltage of the AC input is positive and apply the current of the AC input to the rectifier capacitor. The driver unit outputs first to fourth drive control signals, and drives the first to fourth transistors. The switching device control circuit unit compares the first drive control signal and the second drive control signal with the AC input, and outputs switching device control signals to delay the first to fourth drive control signals based on the extents to delay.

Abstract: A rectifier includes: a rectifying circuit configured to rectify alternating current (AC) power into direct current (DC) power through a switching operation; a driver configured to apply a switching signal to the rectifying circuit; and a signal modulator configured to select a parameter from among parameters of the switching signal based on a frequency of the switching signal, and adjust the selected parameter.

Abstract: A rectifier includes: a rectifying circuit configured to rectify alternating current (AC) power into direct current (DC) power through a switching operation; a driver configured to apply a switching signal to the rectifying circuit; and a signal modulator configured to select a parameter from among parameters of the switching signal based on a frequency of the switching signal, and adjust the selected parameter.

Abstract: A clock and data recovery circuit is disclosed herein. The clock and data recovery circuit includes a phase detection unit, a charge pump, a loop filter, a voltage control oscillator, and a frequency detection unit. The voltage control oscillator has oscillation frequency that is variable in response to a frequency adjustment signal, and outputs an oscillation signal. The frequency detection unit includes a reference clock divider, a counter, and an oscillation frequency control unit. The reference clock divider generates a count-enable signal based on a reference clock signal. The counter generates an oscillation count signal by counting the pulses of the oscillation signal of the voltage control oscillator or the pulses of divided signals resulting from dividing the oscillation signal while the count-enable signal is being enabled. The oscillation frequency control unit compares a target count value with the value of the oscillation count signal, and outputs the frequency adjustment signal.

Abstract: A high power control system includes: a single energy source; an energy source management unit configured to manage the energy source; a controller configured to output a PWM control signal under control of the energy source management unit; a plurality of inverters configured to convert a direct current into an alternating current under control of the PWM control signal of the controller; a plurality of filters coupled to output terminals of the inverters; and a plurality of switches configured to regulate connections between the filters and a load under control of a regulation control signal of the controller.

Abstract: A high power control system includes: a single energy source; an energy source management unit configured to manage the energy source; a controller configured to output a PWM control signal under control of the energy source management unit; a plurality of inverters configured to convert a direct current into an alternating current under control of the PWM control signal of the controller; a plurality of filters coupled to output terminals of the inverters; and a plurality of switches configured to regulate connections between the filters and a load under control of a regulation control signal of the controller.

Abstract: An energy generation system includes an inverter for converting a DC voltage into an AC voltage, a three-phase/two-phase transformer for transforming an output of the inverter into a three-phase/two-phase stationary coordinate system, a phase locked loop for calculating the phase and frequency of an output voltage of the inverter, a phase shifter for generating a current phase reference value, a current reference coordinate transformer for transforming the current phase reference value and the current amplitude reference value into a two-phase stationary coordinate system, a current phase calculator for outputting a current phase calculation value, a current phase calculator for outputting a current amplitude calculation value, a current adjuster for generating a current adjustment signal, an output three-phase transformer for transforming the current adjustment signal into a current adjustment signal in a three-phase stationary coordinate system, and a PWM controller for outputting a PWM control signal.

Abstract: Provided are a solar energy generation system having an adaptive maximum power point tracking function and a method thereof. The solar energy generation system includes: a minimum maintenance voltage determination unit configured to output a minimum maintenance voltage which enables the inverter to maintain an operation thereof corresponding to a grid voltage of the grid; a maximum power point tracking controller configured to determine a maximum power point tracking voltage at a maximum power point of the photovoltaic module, using the minimum maintenance voltage and an output voltage and output current of the photovoltaic module, and to output a reference voltage to track the maximum power point; a voltage calculator configured to calculate a difference between the reference voltage and the output voltage of the photovoltaic module; and a voltage adjuster configured to generate a reference current value using an output of the voltage calculator.

Abstract: A photovoltaic generation system using grid-connected parallel inverters comprises a plurality of photovoltaic generation devices connected in parallel with each other, and a transformer configured to transform and transfer output voltages of the photovoltaic generation devices to a grid, wherein the photovoltaic generation device includes: a photovoltaic module configured to convert photovoltaic energy into DC electrical energy; an inverter configured to convert the DC electrical energy outputted from the photovoltaic module into AC electrical energy; an LC filter configured to remove noise included in the AC electrical energy which is outputted from the inverter; and a Y-connected capacitor group which is connected between one terminal of a reactor in the LC filter and one terminal of the photovoltaic module and is configured to reduce stray current.

Abstract: Provided are a solar energy generation system having an adaptive maximum power point tracking function and a method thereof. The solar energy generation system includes: a minimum maintenance voltage determination unit configured to output a minimum maintenance voltage which enables the inverter to maintain an operation thereof corresponding to a grid voltage of the grid; a maximum power point tracking controller configured to determine a maximum power point tracking voltage at a maximum power point of the photovoltaic module, using the minimum maintenance voltage and an output voltage and output current of the photovoltaic module, and to output a reference voltage to track the maximum power point; a voltage calculator configured to calculate a difference between the reference voltage and the output voltage of the photovoltaic module; and a voltage adjuster configured to generate a reference current value using an output of the voltage calculator.

Abstract: A new and renewable energy generation system includes: an inverter for converting a DC voltage into an AC voltage; a three-phase/two-phase transformer for transforming an output of the inverter into a three-phase/two-phase stationary coordinate system; a phase locked loop for calculating the phase and frequency of an output voltage of the inverter; a phase shifter for generating a current phase reference value; a current reference coordinate transformer for transforming the current phase reference value and the current amplitude reference value into a two-phase stationary coordinate system; a current phase calculator for outputting a current phase calculation value; a current phase calculator for outputting a current amplitude calculation value; a current adjuster for generating a current adjustment signal; an output three-phase transformer for transforming the current adjustment signal into a current adjustment signal in a three-phase stationary coordinate system; and a PWM controller for outputting a PWM co