Abstract: Described herein is a method of operating a power electronic converter device for an electrical power conversion system. The power electronic converter device includes a converter circuit including an input side, an output side, a first converter, and at least one second converter. The second converter includes at least one floating cell with a DC intermediate circuit and semiconductor devices. The method includes: switching the semiconductor devices of the floating cell at switching instants determined with optimized pulse patterns or carrier-based pulse width modulation; determining a fundamental voltage component for the floating cell; and generating the fundamental voltage component in the actual voltage of the floating cell by modifying the switching instants, such that a voltage VC AF of the DC intermediate circuit is lying in a given reference voltage range for balancing the DC intermediate circuit of the floating cell.

Abstract: A method for controlling a converter system includes: determining, with a first controller stage, an output voltage reference for the converter system; generating, with the first controller stage, switching commands for a main converter based on the output voltage reference, such that the main converter converts an input voltage into an intermediate voltage provided at an output of the main converter and following the output voltage reference; and generating, with a second controller stage, switching commands for a floating converter cell connected to the output of the main converter, such that the floating converter cell converts the intermediate voltage into an output voltage provided at an output of the floating converter cell, wherein the floating converter cell comprises a cell capacitor and a semiconductor switch arrangement for connecting and disconnecting the cell capacitor between the output of the main converter and the output of the floating converter cell.

Abstract: A method for controlling a modular converter connected to an electrical grid for active power filtering the electrical grid to compensate for a load connected to the electrical grid, comprises: receiving an actual load current and an actual converter state of the modular converter; determining, from the actual load current and a history of previous load currents, a sequence of future load currents over a prediction horizon; predicting a sequence of future converter states of the modular converter and a sequence of manipulated variables for the modular converter over the prediction horizon by solving an optimization problem based on the actual converter state and the future load currents by minimizing an objective function mapping control objectives to a scalar performance index subject to the dynamical evolution of a prediction model of the modular converter and subject to constraints; and applying a next switching state, which is determined from a first element of the sequence of manipulated variables, to th

Abstract: A method for controlling a first and a second reverse-conducting insulated gate bipolar transistor (RC-IGBT), electrically connected in series, is disclosed. A collector of the first RC-IGBT is electrically connected to a positive pole of a direct current voltage source, and an emitter of the second RC-IGBT is electrically connected to a negative pole of the DC voltage source. Further, an emitter of the first RC-IGBT is electrically connected to a collector of the second RC-IGBT to form an alternating current terminal. A gate voltage is applied to respective gates of the first and second RC-IGBTs, wherein the gate voltage is controlled based on a magnitude and a direction of an output current on the AC terminal and on a command signal alternating between a first and a second value.

Abstract: A method for controlling a modular converter connected to an electrical grid for active power filtering the electrical grid to compensate for a load connected to the electrical grid, comprises: receiving an actual load current and an actual converter state of the modular converter; determining, from the actual I load current and a history of previous load currents, a sequence of future load currents over a prediction horizon; predicting a sequence of future converter states of the modular converter and a sequence of manipulated variables for the modular converter over the prediction horizon by solving an optimization problem based on the actual converter state and the future load currents by minimizing an objective function mapping control objectives to a scalar performance index subject to the dynamical evolution of a prediction model of the modular converter and subject to constraints; and applying a next switching state, which is determined from a first element of the sequence of manipulated variables, to

Abstract: It is provided a mechanical bypass switch device arranged to bypass a converter cell in a power converter. The mechanical bypass switch device includes: a mechanical switch; a mechanical switch actuator arranged to make the mechanical switch conduct when supplied with an electric signal; a first control input; and a second control input. The mechanical bypass switch device is arranged such that a control signal, provided on either one of the first control input and the second control input or on both of the first control input and the second control input, causes the mechanical switch to conduct. A corresponding converter arm and bypass converter are also presented.

Abstract: It is provided a mechanical bypass switch device arranged to bypass a converter cell in a power converter. The mechanical bypass switch device includes: a mechanical switch; a mechanical switch actuator arranged to make the mechanical switch conduct when supplied with an electric signal; a first control input; and a second control input. The mechanical bypass switch device is arranged such that a control signal, provided on either one of the first control input and the second control input or on both of the first control input and the second control input, causes the mechanical switch to conduct. A corresponding converter arm and bypass converter are also presented.

Abstract: A method for controlling a first and a second reverse-conducting insulated gate bipolar transistor (RC-IGBT), electrically connected in series, is disclosed. A collector of the first RC-IGBT is electrically connected to a positive pole of a direct current voltage source, and an emitter of the second RC-IGBT is electrically connected to a negative pole of the DC voltage source. Further, an emitter of the first RC-IGBT is electrically connected to a collector of the second RC-IGBT to form an alternating current terminal. A gate voltage is applied to respective gates of the first and second RC-IGBTs, wherein the gate voltage is controlled based on a magnitude and a direction of an output current on the AC terminal and on a command signal alternating between a first and a second value.