Hitachi Energy Ltd

Abb Power Grids Switzerland Ag

Abb Schweiz Ag

Jerome Fischer

Beat Buchmann

Simon Herold

Luigi Lucano

Martin Klaeusler

Giulia Beanato

A method for operating a power electronic converter comprising at least one power semiconductor device is provided. The method comprises the determination of the at least one current limit, by carrying out a first operation if the temperature of the at least one semiconductor device is above an upper temperature threshold in order to decrease the current limit, and by carrying out a second operation if the temperature of the at least one semiconductor device is below a lower temperature threshold in order to increase the current limit.

Method for operating a power electronic converter, and power electronic converter

A method of discharging a Modular Multilevel Converter (MMC) includes a plurality of phase legs connected in delta configuration. Each leg includes a plurality of series connected submodules, each submodule including an energy storage. The method includes disconnecting the MMC from an electrical grid, discharging the energy storages by means of a circulating current, and reconnecting the MMC to the electrical grid. The discharging includes, for each phase leg, setting a voltage reference, and sequentially selecting submodules in zero state by means of a sorting algorithm for switching each of the selected submodules to plus or minus state until the voltage deviation from the set voltage reference of the energy storage of each submodule in the phase leg is within a predefined range.

Voltage balancing in a Modular Multilevel Converter having delta configuration

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Egerkingen, Switzerland

Jerome Fischer