Modular multi-level converter

Patent metadata

Field	Value
Publication number	US-9680392-B2
Application number	US-201514696137-A
Country	US
Kind code	B2
Filing date	Apr 24, 2015
Priority date	May 13, 2014
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Provided is a modular multi-level converter (MMC) including a plurality of sub-modules including switching elements, and a central control unit which assigns an address to each of the plurality of sub-modules for distinguishing each of the plurality of sub-modules, determines switching operation conditions of the plurality of sub-modules based on the assigned addresses, and outputs switching signals corresponding to the determined switching operation conditions. The central control unit determines a switching sequence of the plurality of the sub-modules according to the sequence of the assigned addresses.

First claim

What is claimed is:

1. A modular multi-level converter comprising:
a plurality of sub-modules comprising switching elements; and
a central control unit configured to:
sequentially assign an address to each of the plurality of sub-modules from the front according to an arranged sequence of the plurality of sub-modules for distinguishing each of the plurality of sub-modules,
determine switching operation conditions of the plurality of sub-modules based on the assigned addresses, and
output switching signals corresponding to the determined switching operation conditions,
wherein the switching operation conditions include a charging operation condition, a discharging operation condition, and a bypassing operation condition, and
wherein the central control unit is further configured to allow discharging operations to be performed sequentially from the sub-module having a lowest address based on a target voltage and charged voltages of the plurality of sub-modules; and
wherein the lowest address is assigned to the front most one of the plurality of sub-modules, and a highest address is assigned to the sub-module which is disposed at the rear most one of the plurality of sub-modules.

2. The modular multi-level converter according to claim 1 ,
wherein a sum of the voltages charged in sub-modules performing the discharging operations correspond to the target voltage, and
wherein the central control unit confirms the charged voltages from the sub-module having the lowest address and determines a switching operation condition of each of the sub-modules to generate an output voltage corresponding to the target voltage.

3. The modular multi-level converter according to claim 1 , wherein when a sub-modules operating under the discharging operation condition are determined, the central control unit stores information on a sub-module having the last address from among the sub-modules operating under the discharging operation condition.

4. The modular multi-level converter according to claim 2 , wherein the central control unit confirms a sub-module which has the last address and has performed a discharging operation at a previous point in time, and allows a discharging operation to be sequentially performed starting from a sub-module which has the next address after the address of the confirmed sub-module.

Assignees

• Lsis Co Ltd

Inventors

• Song Woong Hyub
• Kim Young Woo

Classifications

• H02M2007/4835

  Electricity · mapped topic

• H02M7/49 Primary

  Combination of the output voltage waveforms of a plurality of converters · CPC title

• H02M7/217 Primary

  using semiconductor devices only · CPC title

• H02M5/458

  using semiconductor devices only · CPC title

• H02M7/4835 Primary

  comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage · CPC title