Abstract: The present disclosure relates to a photovoltaic power installation configured to deliver power to a power distribution grid at a point of common coupling, the photovoltaic power installation including a determination unit configured to determine an amount of self-consumed power of the photovoltaic power installation, and a first power inverter configured to generate power in accordance with 1) the determined amount of self-consumed power, and 2) a power level to be delivered at the point of common coupling. The disclosure further relates to an associated method.

Abstract: The disclosure relates to a combiner box including input connections for string lines from a plurality of strings of photovoltaic modules, and output connections for a pair of output lines to an inverter. The combiner box further includes a switching device by means of which the strings are connected to the inverter and which comprises output-side switching contacts and, for each of the strings or for each pair of strings connected in parallel in a fixed manner in the combiner box, at least one separate input-side switching contact, and an overcurrent protection device, which interrupts occurring overcurrents from or to each of the strings or at least from or to each of the pairs of strings connected in parallel in a fixed manner in the combiner box. The switching device includes a switching-contact drive, which is controlled in order to selectively disconnect the strings from the inverter.

Abstract: A method for the communication of system control units with multiple energy generating systems includes receiving request data from the system control units and system data from the energy generating systems at a common gateway, managing the system data and processing the request data in the gateway, and sending control commands to the energy generating systems and/or data responses to the system control units via the gateway. The request data and/or the system data are received in at least two different data models at the gateway, and translated from their respective data models into a metadata model. The translated system data are managed and the translated request data are processed in the gateway, resulting in data responses and/or control commands in the metadata model that are translated back into the data models of the specific system control units and/or energy generating systems, and transmitted to them by the gateway.

Abstract: The power density distribution of a photovoltaic generator of planar extent is determined by measuring an electrical power generated by the photovoltaic generator. Temporal profiles of the measured power with respect to shadow edges migrating across the photovoltaic generator are evaluated taking account of edge direction and edge transverse speed of the respective shadow edge. The power density distribution is reconstructed from the evaluated temporal profiles for different edge directions.

Abstract: In order to distribute power over multiple direct current sources which are connected in parallel to an input-side direct voltage intermediate circuit of a DC/AC transformer, at least one of which direct current sources is connected to the direct voltage intermediate circuit via a DC/DC transformer, wherein the DC/DC transformer can be actuated to change the power fed into the direct voltage intermediate circuit by the direct current source, the power levels of the direct current sources are decreased differently in a decreased operating mode of the DC/AC transformer in which the power of the DC/AC transformer is decreased compared to the sum of the maximum power levels available from all the direct current sources, and by actuating at least the one DC/DC transformer via which the at least one direct current source is connected to the direct voltage intermediate circuit, variation in the power levels of at least one other direct current source is compensated dynamically.

Abstract: The disclosure relates to a method for operating a bidirectional battery converter connected to an AC grid, taking into account the availability of locally generated electrical power. Furthermore, the present disclosure relates to a battery converter comprising measuring devices for detecting the state of charge of a connected battery and comprising a controller, which performs the method.

Abstract: The disclosure relates to an inverter with at least two DC inputs, which are coupled to a common DC link, which is connected to an inverter bridge. At least one of the DC inputs is coupled to an additional DC link. The disclosure also relates to a PV system comprising such an inverter and to a method for controlling such an inverter of a PV system, wherein a power flow from at least one of the DC inputs is directed into the common DC link and/or into the additional DC link on the basis of suitably coordinated control of the DC-DC converter and of an additional DC-DC converter allocated to the additional DC link.

Abstract: The disclosure relates to a detection method for an inverter for detecting a grid fault in a power supply grid, includes determining a grid impedance (Z) and/or the rate of change thereof with respect to time (dZ/dt) and/or a rate of change of an absolute value of the grid impedance (Z) with respect to time (d|Z|/dt), comparing the absolute value and/or a real part and/or an imaginary part of the grid impedance (Z) and/or the rate of change thereof with respect to time (dZ/dt) and/or the rate of change of the absolute value of the grid impedance (Z) with respect to time (d|Z|/dt) with respective predetermined limit values. The method also includes detecting a grid fault state based on the comparison, wherein a distinction is drawn between an islanding situation (AID) and a fault ride through (FRT) situation, and signaling an existing islanding situation (AID) or a fault ride through (FRT) situation as a grid fault state.

Abstract: In order to control a plurality of inverters, which are connected on their input side to a current source each and on their output side to a common grid connection point, electrical variables are measured at the individual inverters and are used for controlling the individual inverters, currents being output by the individual inverters depending on the electrical variables measured at the location of the individual inverters Effects of the connection equipment between the individual inverters and the common grid connection point on currents are determined, electrical variables being measured at the grid connection point and are set in relation to the electrical variables measured at the same time at the individual inverters. The connection equipment between the individual inverters and the common grid connection point is taken into consideration in controlling the individual inverters.

Abstract: The disclosure relates to an inverter having a first housing module, a second housing module, removably connected to the first housing module, and power-electronic components in both housing modules, wherein a cooling air channel, opening in the surroundings of the inverter, is delimited in the circumferential direction partially by the first housing module and partially by the second housing module. The first housing module is configured to mount to an external structure and the second housing module is configured to mount to the first housing module. The cooling air channel extends at a distance to a mounting plane of the inverter defined by the first housing module opposite the external structure.

Abstract: In order to reduce spurious emissions of a current converter or voltage converter having at least one power switch which is actuated with an actuating signal, wherein each actuating signal comprises switch-on pulses spaced apart from one another, and wherein pulse widths of the switch-on pulses are modulated in order to meet a specification for a current or a voltage in or at the current converter or voltage converter, the pulse widths are additionally varied more quickly and more strongly than is appropriate for meeting the specification in order to change the spectrum of the spurious emissions. In this context, changes to the pulse widths when they additionally vary compared to the pulse widths that would result only owing to their modulation to meet the specification are made on the basis of successive groups of changes which each extend over a predefined number of successive switch-on pulses and in which a sum of the changes is zero in each case.

Abstract: A method of operating a transformerless inverter connected on the input side to a generator and on the output side to a multiphase AC grid and comprising a multi-phase inverter bridge with a switch between a midpoint of a DC intermediate circuit on the input side and a terminal for a neutral conductor of the multiphase AC grid, includes feeding electric power from the DC intermediate circuit into the AC grid by the inverter bridge with the switch closed when first operating conditions are present, and opening the switch when there is a transition from the first operating conditions to second operating conditions different from the first operating conditions. The method further includes feeding electric power from the DC intermediate circuit into the AC grid by the inverter bridge with the switch open when the second operating conditions are present, and closing the switch when there is a transition from the second operating conditions to the first operating conditions.

Abstract: A grid-tied inverter for supplying current to a power supply system includes an output bridge arrangement that is actuated via a pulse width modulator, wherein switching times of the output bridge arrangement are determined by using a periodic auxiliary signal, wherein the frequency of the periodic auxiliary signal varies according to a prescribed periodic wobble signal. The inverter further includes a synchronization unit configured to provide phase synchronization of the auxiliary signal to the power supply system, wherein the synchronization unit is configured to adjust a prescribed phase offset of the periodic auxiliary signal in relation to a phase of the power supply system, and a further synchronization unit configured to provide phase synchronization of the periodic wobble signal to the power supply system.

Abstract: The disclosure relates to a method for operating a photovoltaic system for feeding a medium-voltage grid, wherein the photovoltaic system has a photovoltaic generator including a plurality of photovoltaic modules, at least one inverter and at least one medium-voltage transformer. The medium-voltage transformer is connected on the primary side directly to a low-voltage AC output of the inverter, the inverter is connected to the photovoltaic generator via a DC input, and the inverter permits reverse currents from the low-voltage AC output to the DC input. The method is characterized by the fact that in the event that there is insufficient generation of electric power for the feed by the photovoltaic modules, the inverter remains connected on the AC side to the medium-voltage grid via the medium-voltage transformer, and remains connected on the DC side to the photovoltaic generator.

Abstract: For defining an electric potential of input lines of an inverter with respect to ground, in all current-carrying output lines of the inverter capacitors are arranged and charged to a DC voltage in order to shift the electric potential of the input lines with respect to a reference potential present at the current-carrying output lines of the inverter by this DC voltage.

Abstract: A circuitry arrangement includes two-pole connectors for connecting a battery and a further voltage source. The plus pole of one connector and the minus pole of the other connector are directly connected to a plus pole and a minus pole of a DC voltage link. The plus and minus poles of the one connector are connected via a first parallel circuit of a switch and a diode and a first choke connected in series. The minus and plus poles of the other connector are connected via a second parallel circuit of a switch and a diode and a second choke connected in series. A connection between choke ends of the two parallel circuits is electrically conductive at least for alternating currents. The two chokes are magnetically coupled in that their winding senses on a common magnetic core are equal as viewed from the connection between the two parallel circuits.

Abstract: The disclosure relates to a circuit arrangement for actuating a bistable relay including a relay coil of the bistable relay being arranged in a series circuit with a capacitor, wherein the series circuit is connected to a supply voltage (V+) via a first semiconductor switch for switching on the bistable relay and is short-circuited through a second semiconductor switch for switching off the bistable relay. The circuit arrangement includes at least one voltage regulator configured to regulate the voltage present at the relay coil of the bistable relay such that a preset voltage is not exceeded.

Abstract: The disclosure relates to a safety device for a photovoltaic system for feeding into a power supply system, that includes at least one input for connection to a PV generator, at least one output for connection to an inverter, and a switching element for de-energizing the at least one output. The safety device includes an evaluating unit configured to switch the switching element based on a low-frequency signal at the at least one output. The disclosure also relates to a method for operating such a safety device.

Abstract: An inverter apparatus includes an input stage receiving DC electric power from a DC power generator for loading a DC voltage link, a DC/AC converter connected to the DC voltage link and feeding AC electric power into a power grid. The apparatus further includes a bidirectional connection for loading a battery out of the DC voltage link and for loading the DC voltage link out of the battery, and a controller operating the DC/AC converter and the bidirectional connection. The controller receives present values of relevant parameters of the battery including working data at least related to a state of charge and safety data indicating a safety state of the battery from a battery monitoring unit. The controller, in operating the bidirectional connection, considers the working data and is commanded by the safety data.

Abstract: An inductor device has a plurality of inductor windings arranged on a common magnetic core and electrically connected, parallel to one another, to a common connection at one end of the inductor windings. The inductor windings are implemented by a one-part coil form arranged on the common magnetic core and comprising the common connection of the inductor windings. The inductor windings are wound around their common connection and the common magnetic core.