Abstract: A method operates a power converter that contains power converter arms. Each of the power converter arms has switching modules and each of the switching modules has a plurality of semiconductor switches and an energy store. A temperature value for the power converter is ascertained on the basis of a state model of the power converter, wherein the ascertainment is repeated so as to obtain time-related temperature values. A number and a magnitude of temperature swings that have occurred are ascertained from the temperature values, and a remaining service life for the power converter is estimated based on the ascertained number and magnitude. A power converter is configured to carry out the above-described method.

Abstract: A method operates a power converter that contains power converter arms. Each of the power converter arms has switching modules and each of the switching modules has a plurality of semiconductor switches and an energy store. A temperature value for the power converter is ascertained on the basis of a state model of the power converter, wherein the ascertainment is repeated so as to obtain time-related temperature values. A number and a magnitude of temperature swings that have occurred are ascertained from the temperature values, and a remaining service life for the power converter is estimated based on the ascertained number and magnitude. A power converter is configured to carry out the above-described method.

Abstract: A multilevel power converter has at least one phase module with a plurality of modules connected between positive and negative DC voltage connections. The phase module has a first phase module branch connected to the positive DC voltage connection, and a second phase module branch connected to the negative DC voltage connection. Each of the modules has at least two electronic switching elements and an electric energy storage unit. A third phase module branch connects the first phase module branch to the second phase module branch. A switching device connects an AC voltage connection of the multilevel power converter to a first connection node between the first phase module branch and the third phase module branch in a first switch position and connects the AC voltage connection to a second connection node between the third phase module branch and the second phase module branch in a second switch position.

Abstract: The subject of the present invention is an arrangement for switching on a two-way switch of a converter module. A power generation device for providing electric power for switching on the two-way switch is provided that is suitable for converting electromagnetic radiation into electrical power. There is also described a converter module for a modular multi-level converter having the arrangement and a method for producing operational standby for a converter module having a two-way switch.

Abstract: A multilevel power converter has at least one phase module with a plurality of modules (1_1 . . . 1_n; 2_1 . . . 2_n) connected between first and second DC voltage connections. The phase module has a first phase module branch connected to the first DC voltage connection, and a second phase module branch connected to the second DC voltage connection. Each of the modules has at least two electronic switching elements and an electric energy storage unit. A third phase module branch connects the first phase module branch to the second phase module branch. A switching device connects an AC voltage connection of the multilevel power converter to a first connection node between the first phase module branch and the third phase module branch in a first switch position and connects the AC voltage connection to a second connection node between the third phase module branch and the second phase module branch in a second switch position.

Abstract: A modular multilevel converter has a plurality of sub-modules, each of which includes at least two electronic switching elements and an electrical energy storage device. The sub-modules are controlled by a control device. An optical output of the control device of the converter is connected to an input of an optical distributor by way of a first optical waveguide. A plurality of outputs of the optical distributor are individually connected to an optical input of one of the sub-modules, respectively, by way of a second optical waveguide.

Abstract: A modular multilevel converter includes a plurality of sub-modules. Each of the sub modules has at least two electronic switching elements, an electrical energy storage device, two galvanic power terminals, an optical communication input (222) and an optical communication output. A plurality of the sub-modules is connected to a series circuit by way of their communication input and communication output.

Abstract: A device for switching a direct current includes an operating current path which has a mechanical switch, a switch-off current path which is connected in parallel to the operating current path and has a power-electronic switch, and a commutation device which allows commutation of the direct current from the operating current path into the switch-off current path. The commutation device includes a transformer.

Abstract: An apparatus switches a direct current in a high-voltage line. The apparatus contains a multiplicity of switching units, which are arranged so as to form a series circuit in the high-voltage line. Each switching unit in this case contains a switching element and a surge arrester arranged in a parallel circuit with the switching element, the threshold voltage of the surge arrester being higher than a rated voltage of the switching element. A sum of the rated voltages of the switching elements corresponds at least to an operating voltage of the high-voltage line. The switching elements are mechanical switches, and each mechanical switch contains a contact arrangement having two disconnectable contact pieces and is configured to build up an arcing voltage on disconnection of the contact pieces with a magnitude which is higher than the rated voltage of the mechanical switch.

Abstract: A modular multilevel converter has a plurality of sub-modules, each of which includes at least two electronic switching elements and an electrical energy storage device. The sub-modules are controlled by a control device. An optical output of the control device of the converter is connected to an input of an optical distributor by way of a first optical waveguide. A plurality of outputs of the optical distributor are individually connected to an optical input of one of the sub-modules, respectively, by way of a second optical waveguide.

Abstract: A modular multilevel converter includes a plurality of sub-modules. Each of the sub modules has at least two electronic switching elements, an electrical energy storage device, two galvanic power terminals, an optical communication input (222) and an optical communication output. A plurality of the sub-modules is connected to a series circuit by way of their communication input and communication output.

Abstract: A voltage-regulated power converter module includes an electrical charge storage device and a semiconductor switch connected thereto and having a collector, a gate and an emitter, in which the collector-emitter path of the semiconductor switch is switched into a current path between first and second alternating-current terminals of the power converter module. The alternating-current terminals can be interconnected through a bypass switch. The voltage-regulated power converter module is intended to minimize the occurrence of damage in the event of a fault, and allow the multilevel power converter to continue operating without possibly having to use an extremely fast bypass switch for this purpose. To this end, the collector and the gate of the semiconductor switch are interconnected through a circuit configuration, which is configured in such a way that it becomes conductive above a predefined voltage threshold. A power converter is also provided.

Abstract: A switching device for switching bipolar DC currents in a high-voltage system includes at least two electromechanical switching units and a semiconductor switching arrangement. The electromechanical switching units have a first switching status and a second switching status. In the first switching status, the DC current can be passed via at least one of the electromechanical switching units without in this case flowing via the semiconductor switching arrangement. In the second switching status of the electromechanical switching units, the DC current can be passed via the semiconductor switching arrangement and can be switched off.

Abstract: A module for a converter includes submodules, a first coupling inductor and a second coupling inductor which is activatable in the event of a fault. A method for controlling fault currents in a converter is also provided.

Abstract: A device for switching a direct current includes an operating current path which has a mechanical switch, a switch-off current path which is connected in parallel to the operating current path and has a power-electronic switch, and a commutation device which allows commutation of the direct current from the operating current path into the switch-off current path. The commutation device includes a transformer.

Abstract: An apparatus switches a direct current in a high-voltage line. The apparatus contains a multiplicity of switching units, which are arranged so as to form a series circuit in the high-voltage line. Each switching unit in this case contains a switching element and a surge arrester arranged in a parallel circuit with the switching element, the threshold voltage of the surge arrester being higher than a rated voltage of the switching element. A sum of the rated voltages of the switching elements corresponds at least to an operating voltage of the high-voltage line. The switching elements are mechanical switches, and each mechanical switch contains a contact arrangement having two disconnectable contact pieces and is configured to build up an arcing voltage on disconnection of the contact pieces with a magnitude which is higher than the rated voltage of the mechanical switch.

Abstract: A submodule for a high-voltage converter with reduced risk of cross-ignition includes first and second series-connected energy storage devices, first and second semiconductor series circuits connected in parallel with the energy storage devices, respectively, and having first and second, and respectively third and fourth, switched power semiconductor switching units. A first terminal connects to a first potential point between the first and second switching units, a second terminal connects to a second potential point between the third and fourth switching units. A connecting switching unit is connected between the first and second semiconductor series circuits. A first connecting branch with a first diode connects the first potential point and the potential point between the energy storage devices. A second connecting branch with a second diode connects the second potential point and the potential point between the energy storage devices.

Abstract: A submodule for a modular multistage converter contains a first and a second connection terminal, an energy store, and a power semiconductor circuit which is connected to the energy store such that the voltage dropping at the energy store can be generated at the connection terminals in a first switch state and a zero voltage can be generated at the connection terminals in a second switch state. The aim is to provide such a submodule which allows an inexpensive submodule housing to be used while maintaining the same energy storage capacity or which allows an increased energy storage capacity while using the same housing without thereby undermining the protection provided by the submodule housing. This is achieved in that the power semiconductor circuit is connected in parallel to an energy storage branch in which the energy store and a device for limiting a surge current are arranged.

Abstract: A converter for three-phase voltage has three electrically delta-connected series circuits. Each of the series circuits has at least two switching modules connected in series. A control device is connected to the switching modules and can drive the switching modules in such a way that branch currents with a fundamental frequency of the three-phase voltage and with at least one additional current harmonic flow in the series circuits. The additional current harmonic is dimensioned such that it flows in the series circuits of the converter and remains inside the converter.

Abstract: A switching device for switching bipolar DC currents in a high-voltage system includes at least two electromechanical switching units and a semiconductor switching arrangement. The electromechanical switching units have a first switching status and a second switching status. In the first switching status, the DC current can be passed via at least one of the electromechanical switching units without in this case flowing via the semiconductor switching arrangement. In the second switching status of the electromechanical switching units, the DC current can be passed via the semiconductor switching arrangement and can be switched off.