Abstract: A method for operating an electrolysis device, having a converter which is connected on an AC voltage side to an AC voltage grid via a decoupling inductance and draws an AC active power from the AC voltage grid, and an electrolyzer, which is connected to the converter on the DC voltage side, is provided. The method includes operating the electrolysis device, when a grid frequency corresponds to a nominal frequency of the ACT voltage grid and is substantially constant over a time period, with an electrical power which is between 50% and 100% of a nominal power of the electrolyzer, and operating the converter in a voltage-impressing manner, such that an AC active power drawn from the AC voltage grid is changed on the basis of a change and/or a rate of change of the grid frequency in the AC voltage grid.

Abstract: A method for detecting an arc in a circuit including a DC load, a DC source supplying the DC load, and a circuit arrangement between the DC source and the DC load is provided. A power flow between the DC source and an output of the circuit arrangement is cyclically interrupted by a switching circuit, such that the power flow is enabled in an active time window with the first period ?t1 and suppressed in an inactive time window with the second period ?t2. Detection of a current I and/or a voltage U in two consecutive active time windows and comparison of the detected values of current I and/or voltage U of the active time window with the corresponding detected values from the preceding active time window can signal an arc if these values of the active time window differ from the corresponding values of the preceding active time window by more than a threshold value.

Abstract: A container for an energy supply system includes a first section configured to accommodate an air-conditioning unit and/or a control circuit during transport of the container and operation of the energy supply system, and a second section configured to accommodate an energy conversion unit during transport of the container. The energy conversion unit is configured to be selectively removed from the container, and the second section includes a fixing structure for shelf units, such that, after the energy conversion unit has been removed from the container, the shelf units are configured to be installed on the fixing structure and can be fitted with storage modules.

Abstract: An inverter with a rated power of at least 3 kVA includes a first assembly which includes a first printed circuit board and a DC/AC converter stage, and a second assembly which includes a second printed circuit board and an EMC filter for the DC/AC converter stage. The first printed circuit board is mounted on a heat sink and lies substantially flat on the heat sink, and the DC/AC converter stage has converter components which comprise power semiconductors, chokes and link circuit capacitors. The chokes and the link circuit capacitors are arranged together on one side of the first printed circuit board, and the heat sink is arranged on the opposite side of the first printed circuit board, and the chokes and/or the power semiconductors are thermally connected to the heat sink via the first printed circuit board and a thermally conductive material arranged between the first printed circuit board and the heat sink.

Abstract: The disclosure relates to a power electronics device having at least two inverters and a transformer apparatus having a core arrangement, at least one primary winding and at least one secondary winding that wind around the core arrangement at least in sections.

Abstract: A fail-safe operating method for a decentralized power generation plant DG includes determining a leakage capacitance of a generator of the DG before connecting the DG. The method also includes comparing the determined leakage capacitance with a predetermined first limit value, and connecting the DG to a grid only if the determined leakage capacitance is smaller than the predetermined first limit value. A decentralized power generation plant is configured to perform the method.

Abstract: The disclosure describes a method for operating an energy supply installation which is connected to an AC supply grid via a transformer, and exchanges electrical power with the AC supply grid via the transformer. The transformer is connected on a first side to the AC supply grid and on a second side to an AC installation grid of the energy supply installation, wherein the energy supply installation has at least one inverter which exchanges electrical power between a DC unit on the DC side of the inverter and the AC installation grid on the AC side of the inverter. The method includes receiving at least one parameter of the power conversion of the at least one inverter by an installation controller, determining a setpoint AC voltage for the AC installation grid by the installation controller according to the parameter, transmitting the setpoint AC voltage to the transformer.

Abstract: The disclosure relates to an inverter including a first bridge branch with a first phase output, a second bridge branch with a second phase output, a third bridge branch with a third phase output, wherein the phase outputs of the bridge branches can each be connected to a phase conductor of a three-phase power distribution network.

Abstract: A device for current determination includes a shunt and a device for temperature measurement including a printed circuit board, an evaluation unit and a temperature sensor. The printed circuit board has a milled groove which runs spirally around the temperature sensor, so that the temperature sensor is arranged on a printed circuit board plateau defined by the milled groove and is displaceable in a direction that is parallel to a normal vector of a plane defined by the printed circuit board.

Abstract: The disclosure describes a method for detecting an arc in a direct-current (DC) circuit comprising a DC load, a DC source supplying the DC load, and a circuit arrangement arranged between the DC source and the DC load. A power flow P between an input and an output of the circuit arrangement is suppressed by means of a switching circuit through cyclical interruption such that the power flow P is enabled in an active time window with the first period ?t1 and the power flow P is suppressed in an inactive time window with the second period ?t2.

Abstract: The disclosure is directed to a detection device for detecting a fault current (Ifault) at a PV generator and/or at DC lines of a PV installation assigned to the PV generator. The PV generator has at least one first PV string and a second PV string, which are connected to a PV inverter of the PV installation via in each case two DC lines. In this case, the detection device has at least one current transformer and an evaluation circuit connected to the at least one current transformer. The current transformer can be used jointly by the first PV string and the second PV string, wherein a measurement signal of the jointly usable current transformer represents a difference between a first summation current (Isum,1) flowing from the first PV string towards the ground potential (PE) and a second summation current (Isum,2) flowing from the second PV string towards the ground potential (PE).

Abstract: A method and associated system for determining an operating parameter of a PV installation having a plurality of PV modules is disclosed. The PV modules each include a shutdown apparatus connected to a transmission apparatus of the PV installation and has a feed-in operation and a shutdown operation. At least one PV module is equipped with a power-optimizing device which is configured to set an operating point of the PV module in an optimizing operation. The method includes determining a first total electrical power of the PV modules in a non-optimizing operation of the at least one power-optimizing device and in the feed-in operation of the shutdown apparatuses, and determining a second total electrical power of the PV modules in the optimizing operation of all the power-optimizing devices and in the feed-in operation of the shutdown apparatuses.

Abstract: A method is disclosed for stabilizing a DC voltage in a DC grid that includes a DC bus connected to a higher-order grid and to which an energy generating system and at least one load are connected.

Abstract: A changeover device for selectively supplying power to at least one load from a grid or a bidirectional inverter includes an input having a grid neutral conductor connection and a grid phase conductor connection for connection to the grid. The changeover device further includes a first output having an inverter neutral conductor connection and an inverter phase conductor connection for connecting the bidirectional inverter, a second output having a load neutral conductor connection and a load phase conductor connection for connecting the load and a switching circuit, the actuator of which is connected to an actuator input of the changeover device. The switching circuit includes a first and a second normally closed contact and a normally open contact that are connected in an interconnection to the grid phase conductor connection, the inverter phase conductor connection, and the load phase conductor connection. An associated method is also disclosed.

Abstract: A circuit arrangement for balancing a split DC link arranged between a first DC-voltage terminal and a second DC-voltage terminal is disclosed. The first DC-voltage terminal is connected via a first semiconductor switch to a first intermediate point that is connected via a second semiconductor switch to a bridge center point that is connected via a third semiconductor switch to a second intermediate point that is connected via a fourth semiconductor switch to the second DC-voltage terminal. A first terminal of a resonant capacitor is connected to the first intermediate point, and a second terminal of the resonant capacitor is connected to a DC-link center point via a connecting path, in which a resonant inductor is arranged in a series circuit with the third semiconductor switch, and which runs via the second intermediate point.

Abstract: A described method for operating a battery converter in a system, in which, in addition to the battery converter, an inverter, which is connected to a grid, and a DC load are connected to a common intermediate circuit via a DC bus, includes: —controlling an exchange power of the battery converter using a battery, which is connected to the battery converter, depending on a voltage of the intermediate circuit in accordance with a converter characteristic curve, —identifying a decrease in the intermediate circuit voltage below a rectifying value of the permissible AC voltage of the grid connected to the inverter, and—if the decrease is identified, temporarily shifting the converter characteristic curve so that a maximum discharging power of the battery converter is reached at a value of the intermediate circuit voltage that is above or at the rectifying value. A battery converter, which is configured to carry out the method, and a system having such a battery converter are also described.

Abstract: A method for measuring insulation resistance in an inverter that has a DC link circuit and a bridge circuit, connected to the DC link circuit, for driving an AC current via a bridge center tap is disclosed. The method includes connecting the bridge center tap to a grounding point, successively connecting, by way of the bridge circuit, the bridge center tap that is connected to the grounding point to two points of the ungrounded DC link circuit that differ in terms of voltage, and measuring the current flowing from the two points that differ in terms of voltage to the grounding point. The two points of the ungrounded DC link circuit that differ in terms of voltage are selected from a group of points that includes at least one intermediate voltage point of the DC link circuit in addition to two end points of the DC link circuit, such that the voltages present between the two points that differ in terms of voltage and the grounding point do not exceed a predefined voltage limit value.

Abstract: A method for identifying an assignment of phase lines of an electrical distribution grid to connections of an electrical device capable of unbalanced-load operation, wherein the device is connected to a plurality of phase lines of the electrical distribution grid, includes setting target parameters assigned to an unbalanced load profile at each of the connections of the electrical device, detecting a temporal profile of a measurement parameter on each of the plurality of phase lines using a detection circuit, comparing the detected temporal profiles of the measurement parameters with the target parameters of the unbalanced load profile for each of the plurality of phase lines, respectively, and identifying the assignment of the phase lines to the connections on the basis of the comparison.

Abstract: The disclosure relates to a housing of an electrical device for converting electrical power, including a main body and a cover. The cover closes the main body to define a self-contained interior space, wherein electrical and electronic components of the electrical device are arranged in the interior space of the housing. The cover is connected to the main body via a detchable securing structure, which may be arranged in the geometrical center of the cover. An electrical device has a housing of this type.

Abstract: A local power supply system having a grid transfer point for the connection of an energy supply grid has a first transmission line for transmitting electrical energy from the grid transfer point to a first terminal for connecting an arrangement of consumers, and a second transmission line for transmitting electrical energy between the grid transfer point and a second terminal for connecting an arrangement of energy stores. A first disconnector is arranged in the first transition line between the grid transfer point and the first terminal, and a second disconnector is arranged in the second transmission line between the grid transfer point and the second terminal.