US 12,413,157 B2
Controlling a multilevel power converter
Ilhom Gafur, Nuremberg (DE); and Dominik Schuster, Diespeck (DE)
Assigned to Siemens Energy Global GmbH & Co. KG, Munich (DE)
Appl. No. 18/005,701
Filed by Siemens Energy Global GmbH & Co. KG, Munich (DE)
PCT Filed Jul. 17, 2020, PCT No. PCT/EP2020/070325
§ 371(c)(1), (2) Date Jan. 17, 2023,
PCT Pub. No. WO2022/012759, PCT Pub. Date Jan. 20, 2022.
Prior Publication US 2023/0283197 A1, Sep. 7, 2023
Int. Cl. H02M 7/483 (2007.01); H02M 1/084 (2006.01)
CPC H02M 7/4835 (2021.05) [H02M 1/084 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for controlling a modular multilevel power converter, the power converter having at least one phase module branch with a series circuit of modules and each of the modules including an energy storage device and a power semiconductor circuit containing electronic switching elements, the method comprising:
ascertaining a degree of modulation of the phase module branch, the degree of modulation describing a ratio between a phase module branch voltage output by the phase module branch and a maximum phase module branch voltage that is able to be output;
ascertaining a maximum value of the degree of modulation during a preselected time interval; and
using a closed-loop control device to control the maximum value of the degree of modulation to a setpoint value for the maximum value of the degree of modulation.