Abstract:
Disclosed herein is an electric generating system using a solar cell, including: a DC/DC converter that converts output voltage generated from a solar cell into DC voltage and has a converter switching device; a snubber device that has a snubber switch clamping voltage applied to the converter switching device; and a control device that detects the voltage applied to the converter switching device and controls an operation of the snubber switch according to a detected voltage level applied to the converter switching device, thereby increasing the efficiency of the electric generating system using a solar cell while reducing switching loss and conduction loss.
Abstract:
There are provided a power converting apparatus and an operating method thereof, and a solar power generation system. The power converting apparatus for a solar power generation system includes: a power converting unit converting an input signal generated by a solar cell module into an output signal; and a control circuit unit controlling an operation of the power converting unit, wherein the power converting unit includes at least one transformer, and a current sensor and a switching circuit connected to a primary winding of the at least one transformer, and the control circuit unit calculates a voltage and a current of the input signal using a current of the primary winding of the at least one transformer sensed by the current sensor and performs a maximum power point tracking (MPPT) control so that the power converting unit is operated at a maximum power point.
Abstract:
A method for winding a coil on an object, wherein the coil includes a plurality of first coils and a plurality of second coils, may have winding the first coils on an exterior circumferences of the second coils, wherein an outer circumferences of the respective second coil is enclosed and in contact with outer circumference of at least three first coils, and wherein cross-sectional area of the second coil is smaller than that of the first coil, and wherein the outer circumference of the at least three first coils are in contact each other.
Abstract:
Disclosed are a maximum power point tracker, a power conversion controller, a power conversion device having an insulating structure, and a method for tracking maximum power point. The power conversion device includes: a DC/AC converter including a primary DC chopper unit having a primary switch, a transformer, and an AC/AC conversion unit including a secondary switch; a current detector detecting current from an input stage of the DC/AC converter and providing a detected current value; a voltage detector detecting a system voltage from an output stage of the DC/AC converter; and a power conversion controller generating a primary PWM signal to be provided to the primary DC chopper unit and secondary first and second PWM signals, having the mutually opposing phases, to be provided to the AC/AC conversion unit by using the detected current value and the system voltage.
Abstract:
Disclosed herein is an electric generating system using a solar cell which converts a voltage generated in the solar cell into an Alternating Current (AC) voltage, and applies the converted voltage to a power system. The electric generating system includes; a Direct Current (DC)/DC converter that converts the voltage generated in the solar cell into a DC voltage, and has a synchronous rectifier including a synchronous switch; and a controller that detects one of a phase and a voltage of the power system, and selectively connects the synchronous switch of the synchronous rectifier in accordance with one of the phase and voltage of the power system. Here, the electric generating system reduces a conduction loss, and increases overall efficiency of the electric generation system.
Abstract:
An electric generating system using a solar cell improves the quality of output power by including a converter for converting an output voltage generated from the solar cell into a DC voltage in a pulse shape. An inverter converts the DC voltage in the pulse shape into an AC voltage and applies the AC voltage to a power system and a control device for determining whether an erroneous operation of the electric generating system using the solar cell is generated or not based on an output voltage of the solar cell, an output current of the solar cell and a voltage of the power system. At least one inverter switching device among a plurality of inverter switching devices performs a switching at a frequency higher than a frequency during a normal operation at an interval where the erroneous operation is generated.
Abstract:
The present invention provides a switching device and a method for preventing malfunction of the same. The switching device includes: a controller for outputting a plurality of digital control signals; a protecting unit connected to the controller for protecting all signals when the plurality of digital control signals outputted from the controller are simultaneously received at a state of ON; a gate driver connected to the protecting unit for generating a switch control signal by converting the control signal passed through the protecting unit; and a plurality of switches connected to the gate driver for individually performing ON•OFF operations according to each of the switching control signals.
Abstract:
The steam generator for a fuel cell with dual use for heating fuel electrode gas according to the invention is configured as a single unit comprising a steam generator (100) that heats introduced water to generate steam, a steam superheater (200) that is connected to the steam generator (100) and used to supply superheat to the steam in order to elevate the temperature of the steam, and a fuel electrode gas heater (300) that is used to supply heat to the fuel electrode gas in order to elevate the temperature of the fuel electrode gas. The steam generator (100), steam superheater (200) and fuel electrode gas heater (300) are connected with an air electrode exhaust gas flow path through which the air electrode exhaust gas passes, to receive heat supply through heat exchange.
Abstract:
A method of controlling an adjustable antenna of a digital television receiver including (a) storing an effective power of a channel signal received through the antenna in a memory by rotating the direction of the antenna and selecting an antenna pattern when a maximum signal power is detected (b) aligning the stored antenna patterns in order of sizes of the signal powers, and (c) detecting states of the channel signal, a power of the channel signal, a maximum ghost power, and a signal vs. noise ratio and then changing a pattern of the antenna in accordance with the detected states.
Abstract:
A stack fastening device includes a base, on an upper surface of which a stack is loaded, a compression plate, which has a flat configuration and is placed over the stack to press the stack, and a plurality of vertical beams, which are installed on the base to extend vertically so that the upper end portion of the beams projects out through the edge of the compression plate, A thread is formed in an upper end portion of each vertical beam, nuts are threadedly coupled to the thread such that the nuts can be tightened against upper and lower surfaces of the compression plate, and engagement grooves are defined in the upper surface of the compression plate so that a head of a hydraulic cylinder can be coupled to the compression plate.