Hyosung Heavy Industries Corporation

Samsung Electronics Co., Ltd.

Korea Advanced Institute of Science and Technology

Snur & Db Foundation

Hyosung Corporation

Hong Ju Jung

Joo Yeon Lee

Yong Hee Park

Sung Min Oh

Doo Young Lee

Jung Won Hong

Hyun Ho Yoo

Jong-chul Ye

Sung-ho Tak

Jaeheung Yoo

Jae Sung Lee

Ji Hun Kim

Tae Gyun Kim

Sang Ouk Kim

Jae Mock Yi

Kye Young Jeong

Jong Yun Choi

Hang Jun Yang

Jun Chol Lee

In Ho Kim

Byung Kwan Park

Jung Ah Son

Jung Soo Park

Taeyeong Yun

Hong Bean Park

A component grounding system according to one embodiment includes a case for accommodating a plurality of components, a direct current (DC) capacitor disposed on one side of the case and electrically connected to the case, and a bus bar, disposed between the case and the DC capacitor, for connecting the case and the DC capacitor, the bus bar representing an electrode, wherein each of the plurality of components may be connected to the bus bar.

Component grounding system

Proposed is a sub-module of a power converter, the sub-module capable of allowing failure-causing electric current to quickly bypass the sub-module when a failure occurs in the sub-module. A sub-module of a power converter according to an embodiment of the present disclosure, the sub-module including an energy storage unit, at least one power semiconductor circuit connected, in parallel, to the energy storage unit and configured with a plurality of power semiconductor switches and a plurality of freewheeling diodes, and a switching element arranged between two output terminals connected to one of one or more of the power semiconductor circuits, forced to undergo an induced failure when an induced-failure signal is input into a gate terminal thereof, and internally short-circuited, thereby connecting the output terminals to each other.

Sub-module of power converter including bypass switch

Proposed is a submodule of an MMC converter configured to stably supply power to a submodule controller controlling the submodule of an MMC converter. The submodule includes: an energy storage part storing electric energy therein; a plurality of switching elements connected in parallel to the energy storage part to have a shape of a bridge; a plurality of serially-connected resistors connected in parallel to the energy storage part; a plurality of DC-DC converters connected in parallel to a resistor of the plurality of resistors; a power switching part operating to select and output one voltage of voltages output from the plurality of DC-DC converters and a plurality of voltages input from outside; and a submodule controller operating with the voltage output by the power switching part so as to control switching operations of the plurality of switching elements.

Control power for submodules of a MMC converter

Provided are a graphene-based fiber in which a liquid-crystalline aromatic compound is intercalated into a graphene-based material, a graphene-based carbon fiber obtained by carbonizing the graphene-based fiber, and a method of manufacturing the same.

Graphene-based fiber and graphene-based carbon fiber and method of manufacturing the same

The present disclosure relates to a sub-module of a power converter, the sub-module capable of allowing failure-causing electric current to bypass the sub-module when a failure occurs in the sub-module. According to an embodiment of the present disclosure, there is proposed a sub-module of a power converter, the sub-module including an energy storage unit, at least one power semiconductor circuit connected, in parallel, to the energy storage unit and configured with a plurality of power semiconductor switches and a plurality of freewheeling diodes, an auxiliary switching element connected to the energy storage unit, turned on when a failure occurs, and thus allowing electric current from the energy storage unit to pass through, and a main switching element connected in series to an output terminal of the auxiliary switching element, arranged between two output terminals connected to one of one or more of the power semiconductor circuits, forced to undergo an induced failure due to application of a voltage stored in the energy storage unit through the auxiliary switching element, internally short-circuited, and thus connecting the output terminals to each other.

Submodule of power converter having bypass switch

A method for diagnosing a state of a submodule in initial charging of an MMC converter includes identifying, by an upper level controller, a stopped state of the MMC converter; supplying, by the upper level controller, an alternating current (AC) voltage from an AC side to N submodules in the MMC converter when the MMC converter is in the stopped state; charging a capacitor in the submodule with the supplied AC voltage to store an initial charging voltage in the capacitor; determining, by a submodule controller, whether the submodule is in a fault state and when the submodule is in a fault state, transmitting a fault signal to the upper level controller; and detecting, by a voltage detection unit of the submodule the initial charging voltage stored in the capacitor and transmitting the initial charging voltage to the submodule controller.

Method for diagnosing sub-module state during initial charge of MMC converter

An MMC converter linked to a HVDC system and a sub-module constituting the MMC converter are proposed. The sub-module includes: first and second power semiconductor switches connected in series in the same direction, each including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; a capacitor connected in parallel to the first and second power semiconductor switches connected together in series; a first terminal connected to a first node between the first and second power semiconductor switches; a second terminal connected to a second node between the second power semiconductor switch and the capacitor; third and fourth power semiconductor switches connected in series in opposite directions between the first and second terminals, each including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; and a third terminal connected to a third node between the third and fourth power semiconductor switches.

Modular multilevel converter and sub-module thereof

An MMC converter linked to a HVDC system and a sub-module are proposed. The sub-module includes: first and second power semiconductor switches serially connected in the same direction, each including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; a capacitor parallelly connected to the first and second power semiconductor switches serially connected; a first terminal connected to a first node between the first and second power semiconductor switches; a second terminal connected to a second node between the second power semiconductor switch and the capacitor; a third power semiconductor switch of which a side is connected to the second node, the third power semiconductor switch including a semiconductor switch and a diode connected in anti-parallel to the semiconductor switch; and a third terminal connected to a terminal of an AC grid system and connected to the other side of the third power semiconductor switch.

MMC converter and sub-modules thereof

Provided is a hybrid control device for a static synchronous compensator (STATCOM), the device including: a first arithmetic operation unit calculating the deviation between a reference voltage desired to be controlled by the STATCOM and output voltage to be output so as to output the same; a proportional integral (PI) controller performing PI control on the deviation output from the first arithmetic operation unit within a range between a new inductive reactive current maximum value and a new capacitive reactive current maximum value, so as to output a reactive current output value; and a second arithmetic operation unit adding the preset reactive current set value to the reactive current output value output from the PI control unit so as to output a reactive current reference value.

Hybrid control device for static synchronous compensator (STATCOM)

The present invention provides a converter including a plurality of sub-modules connected in series to each other, wherein each of the sub-modules includes a first half-bridge unit including a first energy storage unit, and a plurality of first power semiconductors connected in parallel to the first energy storage unit and connected in series to each other; a second half-bridge unit including a second energy storage unit, and a plurality of second power semiconductors connected in parallel to the second energy storage unit and connected in series to each other; and an auxiliary circuit unit connecting the first half-bridge unit and the second half-bridge unit; wherein the auxiliary circuit unit includes a single third power semiconductor and a single diode.

Converter

The image reconstruction method includes performing a forward projection of a first image of an object using a line integral-based value and a point spread function (PSF)-based value to acquire a forward projection value, and performing a back projection of raw image data using the forward projection value to acquire a second image of the object.

Image processor, image reconstruction method, and radiation imaging apparatus

Disclosed is a high-resolution image reconstruction method using a focal underdetermined system solver (FOCUSS) algorithm. The method comprises the steps of: outputting data for an image of an object; downsampling the outputted data; transforming the downsampled data into low-resolution image frequency data; and reconstructing a high-resolution image from the transformed low-resolution image frequency data by applying focal underdetermined system solver (FOCUSS) algorithm.

Growing community of inventors

Seoul, South Korea

Hong Ju Jung