Abstract: A converter includes an AC side to be connected to an AC network at a connecting point, a grid following controller configured to control a steady state current at the connecting point, and a grid forming controller configured to actively control frequency and voltage at the connecting point. The grid following controller and the grid forming controller share an underlying current controller. A method for operating the converter is also provided.

Abstract: A supply device for a high-power load includes a DC/DC voltage converter disposed between a high-voltage side and a low-voltage side. The DC/DC voltage converter includes a first sub-converter and a second sub-converter. The sub-converters are connected to one another in a converter series circuit between first and second primary-side DC voltage poles. The second sub-converter is connected between first and second secondary-side DC voltage poles. The sub-converters each have at least one AC voltage terminal connected to one another by a coupling device to permit an exchange of electrical power between the first and second sub-converters. The secondary-side DC voltage poles are configured for connection to the high-power load. An arrangement for converting electrical energy into chemical energy with gas generation includes the supply device.

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 converter assembly has multi-phase multi-stage converters which are connected to parallel-connected transformers. The converter assembly contains series-connected partial converters, each having three parallel-connected bipolar phase modules, which are formed of two series-connected converter modules. The connection points of the converter modules form the phase connections for the transformers. The phase modules of a first partial converter consist only of unipolar sub-modules and those of a second partial converter consists only of bipolar sub-modules. A controller respectively reduces at least the partial DC voltage of the second partial converter, wherein the partial DC voltage thereof can be inverted at least until compensating the partial DC voltage of the first partial converter if the direct current exceeds a target value.

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 converter assembly has multi-phase multi-stage converters which are connected to parallel-connected transformers. The converter assembly contains series-connected partial converters, each having three parallel-connected bipolar phase modules, which are formed of two series-connected converter modules. The connection points of the converter modules form the phase connections for the transformers. The phase modules of a first partial converter consist only of unipolar sub-modules and those of a second partial converter consists only of bipolar sub-modules. A controller respectively reduces at least the partial DC voltage of the second partial converter, wherein the partial DC voltage thereof can be inverted at least until compensating the partial DC voltage of the first partial converter if the direct current exceeds a target value.

Abstract: A converter assembly includes a converter unit having AC voltage connection points feeding in or tapping an alternating current, and first and second DC voltage connection points feeding in or tapping a direct current. Parallel series circuits associated with an AC voltage connection point each have first and second circuit connection points respective connected to first and second DC voltage connection points. Each series circuit has submodules connected in series. For each series circuit the AC voltage connection point divides submodules into submodule groups electrically close to first and electrically close to second series circuit connection points. One DC voltage connection point is grounded. For each series circuit the AC voltage connection point divides the submodules into a submodule group electrically close to and a submodule group electrically remote from ground. Submodule groups close to ground have a bipolar submodule and submodule groups remote from ground have unipolar submodules.

Abstract: A converter arrangement includes a converter which can be switched between an AC voltage supply system and a DC voltage circuit and which has converter valves that extend between AC voltage connections and DC voltage connections. Each converter valve has a series connection of bipolar submodules that include power semiconductor devices. The converter arrangement further includes a star point reactor which is located on the AC voltage side of the converter and which has impedance coils that are interconnected to form a grounded neutral point. A suppression filter is connected between the neutral point and a ground connection. The suppression filter is configured to suppress a harmonic of an alternating voltage in the AC voltage supply system.

Abstract: A converter arrangement includes a converter which can be switched between an AC voltage supply system and a DC voltage circuit and which has converter valves that extend between AC voltage connections and DC voltage connections. Each converter valve has a series connection of bipolar submodules that include power semiconductor devices. The converter arrangement further includes a star point reactor which is located on the AC voltage side of the converter and which has impedance coils that are interconnected to form a grounded neutral point. A suppression filter is connected between the neutral point and a ground connection. The suppression filter is configured to suppress a harmonic of an alternating voltage in the AC voltage supply system.

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 converter arrangement has a converter which can be switched between an AC network and a DC voltage circuit and which has power semiconductor valves that extend between AC voltage connections and DC voltage connections. Each power semiconductor valve has a series connection of bipolar submodules that in turn include power semiconductor devices. The arrangement further includes a star point reactor which is arranged on the AC voltage side of the converter and has impedance coils that are connected to a grounded neutral point. In order to better balance the voltages in the DC circuit, the impedance coils have a common coil core.

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 converter arrangement has a converter which can be switched between an AC network and a DC voltage circuit and which has power semiconductor valves that extend between AC voltage connections and DC voltage connections. Each power semiconductor valve has a series connection of bipolar submodules that in turn include power semiconductor devices. The arrangement further includes a star point reactor which is arranged on the AC voltage side of the converter and has impedance coils that are connected to a grounded neutral point. In order to better balance the voltages in the DC circuit, the impedance coils have a common coil core.

Abstract: An apparatus for switching in a DC voltage mains has a switching device for interrupting the flow of current in at least one line of the DC voltage grid. The switching device is connected into the line of the DC voltage grid by way of a first and a second connection. An attenuation member absorbs energy from the applied terminal voltage. The attenuation member has a first and a second node that are electrically connected via an attenuation element, an electrical connection from the first node to the first connection via a first controlled or uncontrolled switching element, and an electrical connection from the first node to the second connection via a second controlled or uncontrolled switching element.

Abstract: A converter arrangement has phase module branches each with two-pole submodules having an energy storage device and a power semiconductor switch. The first phase module branch extends between a first alternating voltage connection and a first direct voltage pole, the second phase module branch extends between the first alternating voltage connection and a second direct voltage pole, the third phase module branch extends between a second alternating voltage connection and the first direct voltage pole, the fourth phase module branch extends between the second alternating voltage connection and the second direct voltage pole. Each submodule can be bridged, independently of the current direction, by a bridging unit. A direct voltage switch is connected between one of the direct voltage poles and the associated direct voltage connection, and a freewheeling path extends between the two direct voltage connections and has a semiconductor element with a blocking and a bypass direction.

Abstract: A DC converter is suitable for continuous operation for connecting high-voltage DC networks having different voltages. The DC converter has a first partial converter and a second partial converter, which are connected in series with each other, forming a converter series circuit. The converter series circuit extends between the DC terminals of a DC connection. The second partial converter extends between the DC terminals of a second DC connection. The first partial converter and the second partial converter are connected to each other via a power exchange device, such that the exchange of electrical power between the first partial converter and the second partial converter is made possible via the power exchange device.

Abstract: A DC-DC converter for connecting high-voltage DC networks has series-connected sub-converters. The high-voltage DC networks which can be connected to the DC-DC converter can have different transmission symmetries by way of power exchanging devices and additional power exchanging devices. Thus, a symmetrical monopole can be connected to an asymmetrical bipolar network using the invention.

Abstract: A DC-DC converter for connecting high-voltage DC networks has series-connected sub-converters. The high-voltage DC networks which can be connected to the DC-DC converter can have different transmission symmetries by way of power exchanging devices and additional power exchanging devices. Thus, a symmetrical monopole can be connected to an asymmetrical bipolar network using the invention.

Abstract: A DC converter is suitable for continuous operation for connecting high-voltage DC networks having different voltages. The DC converter has a first partial converter and a second partial converter, which are connected in series with each other, forming a converter series circuit. The converter series circuit extends between the DC terminals of a DC connection. The second partial converter extends between the DC terminals of a second DC connection. The first partial converter and the second partial converter are connected to each other via a power exchange device, such that the exchange of electrical power between the first partial converter and the second partial converter is made possible via the power exchange device.

Abstract: An apparatus for switching in a DC voltage mains has a switching device for interrupting the flow of current in at least one line of the DC voltage grid. The switching device is connected into the line of the DC voltage grid by way of a first and a second connection. An attenuation member absorbs energy from the applied terminal voltage. The attenuation member has a first and a second node that are electrically connected via an attenuation element, an electrical connection from the first node to the first connection via a first controlled or uncontrolled switching element, and an electrical connection from the first node to the second connection via a second controlled or uncontrolled switching element.