Abstract: A submodule for a modular multilevel converter has nine semiconductor switches that can be switched off, four capacitors, six network nodes, and two terminals. The components are mounted such that different voltages are generated between the terminals of the submodule by controlling the semiconductor switches. This arrangement of components substantially improves the behavior of the converter and of the submodule in the event of a fault.

Abstract: A submodule for a modular multilevel converter has nine semiconductor switches that can be switched off, four capacitors, six network nodes, and two terminals. The components are mounted such that different voltages are generated between the terminals of the submodule by controlling the semiconductor switches. This arrangement of components substantially improves the behavior of the converter and of the submodule in the event of a fault.

Abstract: A submodule for a modular multilevel converter has ten semiconductor switches that can be switched off, four capacitors, six network nodes, and two terminals. The components are mounted such that different voltages are generated between the terminals of the submodule by controlling the semiconductor switches. This arrangement of components substantially improves the behavior of the converter and of the submodule in the event of a fault.

Abstract: A switchable longitudinal voltage source has a first feed connection for feeding in a first current, a first output connection for outputting the first current, a second feed connection for feeding in a second current, and a second output connection for outputting the second current. An electrical energy store has a first connection and a second connection coupled to the output connections. The switchable longitudinal voltage source further has a center terminal of a first series circuit which directly forms the first output connection or terminal and a center terminal of a second series circuit which directly forms the second output connection or terminal.

Abstract: A switchable longitudinal voltage source has a first feed connection for feeding in a first current, a first output connection for outputting the first current, a second feed connection for feeding in a second current, and a second output connection for outputting the second current. An electrical energy store has a first connection and a second connection coupled to the output connections. The switchable longitudinal voltage source further has a center terminal of a first series circuit which directly forms the first output connection or terminal and a center terminal of a second series circuit which directly forms the second output connection or terminal.

Abstract: A longitudinal voltage source interconnects into a first line and a second line and feeds a longitudinal voltage into each of the two lines. The voltage source has first and second H-bridge circuits, each with four switches, and with outer terminals and center terminals. The center terminals are connectable to disconnected locations of the first and second lines. A capacitor has a first capacitor terminal connected to the two first output terminals of the two H-bridge circuits and a second capacitor terminal connected to the two second output terminals of the two H-bridge circuits. One or more switching modules are connected between the first capacitor terminal and the first output terminals of the first and second H-bridge circuits, and one or more switching modules are connected between the second capacitor terminal and the second output terminals of the first and second H-bridge circuits.

Abstract: A modular converter assembly has at least one AC voltage terminal and at least two DC voltage terminals. The DC voltage terminals are formed by the outer terminals of a series circuit and the AC voltage terminal is formed by the connecting node between two sub-circuits of the series circuit. Capacitors of submodules of the subcircuits are activated or deactivated based on their capacitor voltages. The capacitors are operated exclusively in a unipolar mode or exclusively in a bipolar mode. In a time period in which the temporal mean value of the current flowing through the sub-circuit has a different sign than the actual current flowing through the sub-circuit, capacitors operating in a unipolar mode are preferred over capacitors operating in a bipolar manner. That is, the unipolar capacitors are reactivated or remain activated. A selection loop is carried out repeatedly to select the capacitors for activation or deactivation.

Abstract: A modular converter assembly has at least one AC voltage terminal and at least two DC voltage terminals. The DC voltage terminals are formed by the outer terminals of a series circuit and the AC voltage terminal is formed by the connecting node between two sub-circuits of the series circuit. Capacitors of submodules of the subcircuits are activated or deactivated based on their capacitor voltages. The capacitors are operated exclusively in a unipolar mode or exclusively in a bipolar mode. In a time period in which the temporal mean value of the current flowing through the sub-circuit has a different sign than the actual current flowing through the sub-circuit, capacitors operating in a unipolar mode are preferred over capacitors operating in a bipolar manner. That is, the unipolar capacitors are reactivated or remain activated. A selection loop is carried out repeatedly to select the capacitors for activation or deactivation.

Abstract: A longitudinal voltage source interconnects into a first line and a second line and feeds a longitudinal voltage into each of the two lines. The voltage source has first and second H-bridge circuits, each with four switches, and with outer terminals and center terminals. The center terminals are connectable to disconnected locations of the first and second lines. A capacitor has a first capacitor terminal connected to the two first output terminals of the two H-bridge circuits and a second capacitor terminal connected to the two second output terminals of the two H-bridge circuits. One or more switching modules are connected between the first capacitor terminal and the first output terminals of the first and second H-bridge circuits, and one or more switching modules are connected between the second capacitor terminal and the second output terminals of the first and second H-bridge circuits.