Hyosung Heavy Industries Corporation

Hyosung Corporation

Jong-Yun Choi

June-Sung Kim

Hong-Ju Jung

Jung-Soo Park

Doo-Young Lee

A Modular Multilevel Converter (MMC) includes multiple sub-modules connected in series with each other and a controller for controlling on/off switching of the sub-modules, in which the multiple sub-modules include N sub-modules that participate in the operation of the MMC and M redundant sub-modules for replacing at least one N sub-modules when the at least one N sub-modules fail, and the controller switches on a sub-module if a carrier signal assigned thereto is higher than a preset reference signal, and switches off the sub-module if the carrier signal assigned thereto is lower than the preset reference signal.

Modular multilevel converter

Provided is a power control apparatus for sub-modules in an MMC, which controls stable supply of power to sub-modules in MMC connected to an HVDC system and a STATCOM. The power control apparatus has at least one first resistor connected between P and N buses of MMC; a second resistor connected in series with the first resistor; a switch connected in series with the second resistor; a third resistor connected in parallel with the second resistor and the switch which are connected in series; a Zener diode connected in parallel with the third resistor; and a DC/DC converter connected between both ends of the Zener diode and configured to convert voltage across both ends of the Zener diode into low voltage, and supply the low voltage to the sub-modules, wherein a magnitude of current flowing through the Zener diode is controlled depending on ON/OFF switching of the switch.

Power control apparatus for sub-module of MMC converter

The present invention relates to a modular cooling apparatus for a high-voltage direct-current transmission system. A sub-module () according to the present invention comprises a power unit () in the front and a capacitor unit () in the rear, and a heat sink () for discharging heat generated from the interior is provided in an interior space () of a power unit housing () forming the exterior of the power unit (). A coolant path () is provided in the interior of the heat sink (). The entrance and exit of the coolant path () are located adjacent to the bottom surface of the interior space (). Connecting couplers () for supplying coolant to the interior space () are provided on the sloped surface () on the bottom end of the front surface () of the power unit housing (). The sloped surface () is formed so as to face the ground at an angle. On both side surfaces of the power unit housing () are pass-through parts (), each of which is provided with a louver plate () having louvers () to allow air to circulate between the interior space () and the outside. As such, according to the present invention, heat is dissipated more effectively while damage to the sub-module () due to coolant leakage does not occur.

Modular cooling apparatus for high-voltage direct-current transmission system

Disclosed herein is a power supply apparatus for a sub-module controller of a Modular Multilevel Converter (MMC), which supplies driving power to the sub-module controller of an MMC connected to a High Voltage Direct Current (HVDC) system. The power supply apparatus includes a bridge circuit unit including N (N&#x2265;2, integer) energy storage units for storing a DC voltage in series-connected sub-modules in the MMC and multiple power semiconductor devices connected in parallel with the N energy storage units in a form of a bridge; and a DC/DC converter for converting a voltage output from output terminals formed between both ends of n (1&#x2264;n&#x3c;N) series-connected energy storage units, among the N energy storage units, into a low voltage and supplying the low voltage to the sub-module controller.

Power supply device for sub-module controller of MMC converter

Provided is a module replacement device of a high voltage direct current transmission system. In the device, a replacement base is provided in a structure by using a support member such that a sub-module movably provided at a fixing base of the structure can be replaced by being withdrawn outside of the structure. Further, the replacement base can easily and firmly be provided in the structure such that the module can be replaced in an easy and safe manner.

Module replacement device of high voltage direct current transmission system

The present invention relates to a power control apparatus for sub-modules in a Modular Multilevel Converter (MMC), which controls the supply of power to sub-modules in an MMC connected to an HVDC system and to a STATCOM. The power control apparatus includes a half-bridge circuit unit for switching multiple switches, converting an input voltage across P and N buses of the MMC into a relatively low voltage, and outputting the low voltage; a transformer for transferring the low output voltage (primary side), output through switching of the switches in the half-bridge circuit unit via switching of the switches, to a secondary side of the transformer; a DC/DC converter for converting an output voltage on the secondary side of the transformer; a photocoupler for outputting a reference signal corresponding to a magnitude of the secondary side output voltage of the transformer; a Pulse Width Modulation (PWM) control unit for controlling switching of the switches in the half-bridge circuit unit in response to the reference signal output from the photocoupler; and a starting circuit unit for supplying an initial starting voltage to the PWM control unit, wherein the PWM control unit is started in response to the starting voltage initially supplied from the starting circuit unit, and is configured to control switching of the switches in response to the reference voltage received from the photocoupler, and to receive the secondary side output voltage of the transformer as an operating voltage depending on the switching, thus being operated.

A technology is disclosed for controlling switching of power converters included in a power converting system. Phase angles are allocated to a plurality of sub-units corresponding to the power converters, and the respective sub-units create local switching carriers based on the allocated phase angles. The sub-units compare a reference AC voltage with the local switching carriers, and switch the power converters according to the result of the comparison.

Growing community of inventors

Hwaseong-si, South Korea

Jong-Yun Choi