Sungkyunkwan University

Samsung Electro-mechanics Co., Ltd.

Qit Co., Ltd.

Chung Yuen Won

Tae Won Lee

Yong Hyok Ji

Jin Wook Kim

Young Ho Kim

Byoung Kuk Lee

Tae Hoon Kim

Doo Young Song

Dong Seong Oh

Min Ho Heo

Jae Hyung Kim

Don Sik Kim

Hoon Gi Lee

Tae Gyu Kim

Chang Gyun An

Jong Soo Kim

Gyu Yeong Choe

Mi Na Kim

Bong Yeon Choi

Jun Sin Yi

Jun Gu Kim

Hee Sung Moon

Jeong Min Ko

Kyoung Min Kang

Kwang Su Na

Tae Yong Lee

Jae Sun Won

Jeong Kyu Park

Se Ho Lee

Jong Mu Lee

Ku Yong Kim

Kwang Soo Choi

Sung Yong Kim

Song Wook Hyun

Joung Hwan Bae

Bo Hyun Baik

The present invention relates to a control method which can perform, although a line-to-ground fault occurs in phase 1, coordinate transformation to separate the line-to-ground fault of phase 1 without unnecessary power outage by utilizing remaining normal phases, and apply transformed space vector pulse width modulation (SVPWM) to the converted coordinates, and the present invention has been made in view of the above problems, and it is an object of the present invention to provide a method of controlling space vector pulse width modulation (SVPWM), which applies zero voltage to ground-faulted phase 1 and makes an inverter operate normally with only the remaining sound phases in order to prevent unnecessary loss generated as even other sound phases are blocked when a single line-to-ground fault occurs. According to the device, method, and computer program of the present invention for controlling space vector pulse width modulation using a 3-phase 4-leg inverter under a single line-to-ground fault in an islanded microgrid, since available voltage switching vectors are limited as phase 1, in which a line-to-ground fault has occurred, and phase n are restricted to have the same switching state, a novel coordinate transformation may be performed to compensate for the distortions generated therefrom, and since a novel space vector pulse width modulation (SVPWM) method that can be appropriately applied to the transformed coordinates can be provided, the problem of inducing loss of power and reducing the life of devices by unnecessarily cutting off even the sound phases can be solved even when a line-to-ground fault occurs.

Device for controlling space vector pulse width modulation using 3-phase 4-leg inverter under single line-to-ground faults in islanded microgrids and method thereof

A method for controlling a fault of a three phase four wire interlinking converter system according to one embodiment of the present disclosure comprises obtaining a first d-q-o coordinate plane based on an internal phase angle of output voltage produced from each phase of an inverter; converting the first d-q-o coordinate plane to a second d-q-o coordinate plane based on the o-axis configured differently from the first d-q-o coordinate plane; obtaining an output voltage vector for determining a fault location by performing d-q transform on the second d-q-o coordinate plane; determining occurrence of a fault and an area related to the fault based on the output voltage vector; and in the occurrence of the fault, allocating a zero voltage vector to the area related to the fault.

Method for controlling fault using switching technique of three phase four wire interlinking converter

Disclosed herein is a power supply circuit for a gate driver. The power supply circuit for the gate driver includes a negative voltage generator configured to generate a negative voltage by receiving an input voltage, wherein the negative voltage generator includes a tank capacitor configured to be charged by receiving the input voltage through a charge path, a discharge switch configured to form a discharge path when the tank capacitor is discharged, and a negative voltage generation capacitor arranged on the discharge path and configured to generate the negative voltage by storing electric charges discharged from the tank capacitor when the tank capacitor is discharged.

Power supply circuit for gate driver and gate driver circuit of floating switch having the same

In a method of efficiently managing and extending life of a battery bank, it is identified whether lifespan characteristic value of a battery bank unit reaches a predetermined threshold value of lifespan extension, by monitoring a lifespan characteristic value of an individual battery bank unit. While the other battery bank units normally supply power, a high-frequency electric pulse is applied to an identified battery bank unit through a DC/DC converter. Thus, materials preventing an electrochemical reaction accumulated on an electrode are removed.

Method and apparatus for managing life of battery bank

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.

Maximum power point tracker, power conversion controller, power conversion device having insulating structure, and method for tracking maximum power point thereof

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.

DC/DC converter, and electric generating system using solar cell having the same

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 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.

Electric generating system using solar cell

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.

Electric generating system with a controller controlling a snubber device

There is provided an apparatus for the anti-islanding of a power conditioning system. The apparatus for the anti-islanding of a power conditioning system according to the present invention is applied to a power conditioning system including a DC/DC converter and a DC/AC inverter in order to transfer power from a solar cell array to a grid. The apparatus for the anti-islanding of a power conditioning system may include an injection signal generator generating an injection signal, an adder generating a final fundamental wave command value, a main controller performing the power control according to the final fundamental wave command value and stopping the operation of the power conditioning system when the level of the detected injection signal has reached the predetermined reference level or more, and an injection signal detector detecting the injection signal included in voltage and providing them to the main controller.

Apparatus and method for the anti-islanding of power conditioning system

There is provided an apparatus and method for controlling a switch of a flyback converter for a solar generating system. The apparatus for controlling a switch of a flyback converter for a solar generating system includes: an MPPT controller generating a current command value for a maximum power point tracker of a solar cell module, based on input voltage, input current, and output voltage of the flyback converter; a current controller generating a current control signal for tracking the current command value; an output current command value generator generating the phase and magnitude command value of the output current, based on the phase of the output voltage and the current control signal; and a switch controller controlling the main switch of the flyback converter, based on the phase and magnitude command value of the output current, thereby simplifying a circuit while solving disadvantages of a discontinuous conduction mode and a boundary conduction mode.

Apparatus and method for controlling switch of flyback converter for solar generating system

There are provided an apparatus and method for charging and discharging a photovoltaic PCS integrated battery applied to a system that includes a first DC/DC converterconnected to a solar cell, a DC/AC inverter, a DC link unitconnected in common to output terminals of the first DC/DC converterand the DC/AC inverter, and a second DC/DC converterhaving a bidirectional DC/DC conversion function connected between the DC rink unitand the battery. The present invention calculates the amount of photovoltaic power produced by the solar cellbased on voltage and current detected in the voltage/current detector, determines one of predetermined control modes according to the amount of photovoltaic power and the connection or not of the battery, and controls the first DC/DC converter, the second DC/DC converter, and the DC/AC inverter according to the determined control mode.

Apparatus and method for charging and discharging photovoltaic PCS integrated battery

There are provided a method and an apparatus for generating a current command value for tracking the maximum power point of a solar energy generating system. The apparatus includes: a voltage detector detecting a voltage input into the flyback power converter; a first calculator calculating an output power from the detected input voltage; a second calculator calculating a power variation based on the calculated output power and a voltage variation of the input voltage; and a current command value generator generating a current command value for tracking the maximum power point of the solar cell module from the calculated voltage variation and the calculated power variation. Accordingly, a current command value after calculating an output power may be generated with only a voltage detector, without a current detector, thereby reducing the costs of a solar energy generating system by decreasing the costs for a high-priced current detector, and simplifying circuit.

Method and apparatus for generating current command value for tracking maximum power point in solar energy generating system

There are provided an apparatus and a method for controlling the power quality of a power generation system. According to the present invention, there is provided an apparatus for controlling the power quality of a power generation system including a DC/AC inverter converting DC voltage into AC voltage and supplying inverter current to a grid, including: a grid voltage phase follower generating a grid signal; a fundamental extractor extracting a magnitude of a fundamental wave of a load current introduced into a non-linear load connected between the DC/AC inverter and the grid; a first calculator subtracting a preset current compensation value from the magnitude of the fundamental wave from the fundamental extractor; and a second calculator generating an inverter current instruction value for the DC/AC inverter by using the output value of the first calculator and the grid signal and the load current from the grid voltage phase follower.

Apparatus and method for controling power quality of power generation system

Growing community of inventors

Gyunggi-do, South Korea

Chung Yuen Won