Abstract: A method for controlling an electrical power which flows into or out of an electrical subnetwork via a connection point is disclosed. The subnetwork has at least one electrical load, and the electrical load is connected to a control device via a communication connection, the electrical power flowing via the connection point is measured and a maximum power consumption of the electrical load is set by means of the control device on the basis of the electrical power flowing via the connection point. A device for connecting a multiphase subnetwork, which has an energy production installation and an energy store, to a superordinate multiphase alternating voltage network is configured to transmit electrical power between the alternating voltage network and the subnetwork and comprises an AC/AC converter having a network connection, two inverter bridge circuits with an interposed intermediate circuit and a subnetwork connection.

Abstract: A method for detecting a potential-induced degradation (PID) of PV modules of a PV installation includes operating a PV generator at a maximum power point (MPP), at a first generator voltage (U1) and first generator current (I1), and at a second generator voltage (U2) and second generator current (I2), where a first power (P1) at the first generator voltage (U1) is in a predefined first ratio V1=P1/PMPP and V1?1, with the power (PMPP) at the maximum power point (MPP) of the PV generator, and where a second power (P2) at the second generator voltage (U2) is in a predefined second ratio V2=P2/P1 and V2<1, with the first power (P1) of the PV generator, and where a quantity Y that characterizes a progress of the potential-induced degradation (PID) is determined from the values of the voltages (U1, U2) and/or the currents (I1, I2).

Abstract: A method and associated apparatus for feeding electric power from a photovoltaic system via a grid connection point into an AC grid having a low short-circuit power is disclosed. The method includes connecting a DC voltage side of at least one first inverter of the photovoltaic system to a photovoltaic generator and an AC voltage side of the at least one first inverter to the grid connection point, wherein the at least one first inverter is operated as a current source, and connecting an AC voltage side of a second inverter of the photovoltaic system to the grid connection point, wherein the second inverter is operated as a voltage source based on measurement values of an AC voltage measured in the region of the photovoltaic system and a predefined characteristic curve.

Abstract: A system for distributing locally generated energy from at least one renewable DC source to a plurality of local load units of the system, including, for each load unit: an input terminal configured to connect to a grid, and an output terminal configured to connect to at least one load. Further for each load the system includes an inverter including an inverter input and an inverter output, wherein the inverter input is connected to the at least one renewable DC source and the inverter output is connected to the input terminal and to the output terminal of the respective load unit, and wherein the inverter is configured to convert a direct current at the inverter input into an alternating current at the inverter output.

Abstract: An inverter for a photovoltaic system includes a substantially planar baseplate having a front and a rear, wherein the rear forms an outer rear wall of the inverter, and having at least one platform-like elevation that rises in the direction of the front of the baseplate. The inverter also includes a printed circuit board having one or more heat-generating components mounted thereon, wherein the printed circuit board is installed on the baseplate such that the one or more heat-generating components are arranged on the printed circuit board in the region of the platform-like elevation and are in thermal contact with the platform-like elevation. The inverter further includes a potting compound that fills a space on the front of the baseplate and surrounds at least partially the printed circuit board, and a cover arranged on or in the potting compound that adjoins the baseplate, so that the baseplate and the cover surrounding at least part of the potting compound form a housing.

Abstract: Disclosed is an electrical unit with a first port configured to be operatively connected to an AC-grid, a second port configured to be operatively connected to an AC-load, and a third port to be operatively connected to an AC-side of a first inverter. The electrical unit includes a first choke arranged between the third port and the second port. The electrical unit is configured to transfer electrical power provided by the first inverter from the third port via the first choke to the second port. The electrical unit is configured to provide grid-forming electrical power to the second port in case of disconnection from the AC-grid at the first port. Further disclosed is a backup power system and a method for operating a backup power system.

Abstract: An electrical or electronic device with a housing which includes a rear wall and a side wall peripherally surrounding the rear wall, contains a first region and a second region. The first region includes a shielding from the second region with respect to electromagnetic compatibility (EMC). The housing includes a stepped projection on an inner side of the side wall and/or of the rear wall. The shielding for electromagnetic compatibility includes a shielding plate, by means of which the first region is delimited from the second region. An electrical connection of the shielding plate to the side wall and/or to the rear wall is formed in that a peripheral region that delimits the shielding plate areally overlaps the stepped projection, at least along most of its length, and is fastened on it.

Abstract: The present disclosure discloses a control processing method for an inverter device having an H5 topological structure. The control processing method includes: when a power grid supplies power normally, using a unipolar H5 PWM modulation mode to enable the inverter device to work in a grid-connected power generation mode; when the power grid supplies power abnormally or the power grid is in outage for a short time, using a unipolar H5 PWM constant-voltage modulation mode to enable the inverter device to work in an off-grid power generation mode; and when the power grid is in outage for a long time, using an H5-1 PWM constant-voltage modulation mode to enable the inverter device to work in an emergency SPS power generation mode.

Abstract: A method for operating an energy generation system containing a photovoltaic generator and an inverter, wherein electric power is transferred between the inverter and an AC voltage grid, and wherein the transferred electric power comprises an active power (P) and a reactive power (Q) is disclosed. The method includes operating the photovoltaic generator, in a first operating mode, at a maximum active power point (MPP) by way of the inverter, and setting the active power (P) of the photovoltaic generator via the inverter in a second operating mode depending on a grid frequency instantaneous value (f) and on a grid frequency rate of change (df/dt), and in the second operating mode, setting the reactive power (Q) depending on a grid voltage instantaneous value (U) and on a grid voltage rate of change (dU/dt).

Abstract: A method for detecting a contact fault in a photovoltaic system is disclosed. The photovoltaic system includes an inverter and a photovoltaic generator connected to the inverter via DC current lines. The inverter includes a transmitter for coupling a first AC voltage signal having communication frequencies in a first frequency range between 125 kHz and 150 kHz into the DC current lines. A receiver is configured to couple out the first AC voltage signal and is arranged at the photovoltaic generator. A decoupling circuit is configured to decouple the impedance of the photovoltaic generator is arranged between the inverter and the photovoltaic generator, such that the photovoltaic generator is AC decoupled from a transmission path between the inverter and the decoupling circuit.

Abstract: A disclosed intermediate circuit arrangement includes first and second partial circuit boards of identical design having a series circuit of at least two capacitor banks. The partial circuit boards each have a terminal strip having a positive intermediate circuit connection, a negative intermediate circuit connection, and a central connection. The circuit arrangement also includes a connecting circuit board for electrically connecting the respective connections of the terminal strips of the two partial circuit boards to one another. The connecting circuit board is a multi-layer circuit board with two outer metal layers and at least two inner metal layers arranged between the outer metal layers.

Abstract: The disclosure discloses a control panel and an outdoor device with the control panel, which can discharge accumulated water in the control panel to prevent water accumulation. A control panel for preventing water accumulation includes a display sheet which is transparent or translucent and used for covering and protecting a circuit board and/or component, an interface label having functional areas allowing a user to observe or operate the circuit board and/or component, and an adhesive layer connected between areas of the display sheet and the interface label except for the functional areas so as to adhere the display sheet and the interface label together. Cavities are formed between the functional areas of the interface label and corresponding locations of the display sheet so as to form a display window and/or key windows. The water guiding grooves are provided in the adhesive layer for communicating the cavities with the outside so as to discharge the accumulated water.

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: A inductor arrangement has a toroidal core with a central opening, a winding which is arranged around the core and has two winding ends, and an electrically insulating insert which is inserted into the central opening in a clamping manner. Here, the winding ends are inserted into the insert in a clamping manner.

Abstract: A converter includes an input configured to be connected to a DC source, at least one transducer module coupled to the input, and comprising a first, a second and a third bridge arm, wherein each of the bridge arms respectively has a phase output, and a common DC link circuit coupled to the input and the bridge arms. The first and second bridge arms are configured to provide a first power in the form of alternating current at their respective phase outputs. An energy store is configured to be connected to the phase output of the third bridge arm, and the third bridge arm is configured to exchange a second power between the DC source and the energy store and between the energy store and the DC link circuit/ A control unit is configured to control the bridge arms in such a manner that the sum of the first power and the second power corresponds to a constant set point.

Abstract: A circuit arrangement includes a power semiconductor switch, a freewheeling diode, and a storage choke having a core and a winding coupled between a first choke terminal and a second choke terminal. The storage choke is configured to conduct a current flowing across the power semiconductor switch. The arrangement also includes a driver circuit configured to drive the power semiconductor switch via the control terminal thereof.

Abstract: A solar module includes a safety circuit, and a series circuit of bypass diodes, which is arranged between solar module connections, wherein the bypass diodes have bypass connections at both ends and all connecting points of the series circuit of bypass diodes. The solar module also includes a series circuit of solar partial modules having partial module terminals at both ends and all connecting points of the series circuit of solar partial modules, wherein each bypass diode is associated with precisely one solar partial module, and a plurality of semiconductor switches configured to disconnect the solar module connections from voltage at an associated partial module terminal when a disconnection signal is received by the safety circuit.

Abstract: A method for determining a system power, which is maximally possible at a point in time, of a photovoltaic system, comprising a plurality of photovoltaic generators, wherein the photovoltaic system is not operated at the maximally possible system power at the point in time, and wherein at least some of the photovoltaic generators of the plurality of photovoltaic generators are operated at different operating points at the point in time, is disclosed.

Abstract: A method for a single-fault-tolerant determination of an isolation resistance of a photovoltaic system including an inverter and a solar generator connected thereto is disclosed. The isolation resistance is determined as a function of a test voltage drop in a resistor network, wherein the resistor network is connected to a variable voltage source by way of a first terminal, to a first pole of the solar generator by way of a second terminal and to a ground terminal of the inverter via an isolation relay by way of a third terminal. A capacitor is disposed between the ground terminal and the first pole of the solar generator.

Abstract: In large PV power plants, grounding of individual PV modules may lead to problems. The present invention overcomes such problems. The basis for the invention is a PV power plant comprising one or more PV generators, each comprising a PV string and an inverter with a DC input and an AC output. The PV string comprises at least one PV module and is electrically connected to the DC input of the inverter. The inverter comprises means for controlling the DC potential at the DC input depending on the DC potential at the AC output. The AC outputs of the inverters are coupled in parallel. The novel feature of the invention is that the PV power plant further comprises an offset voltage source, which controls the DC potential at the AC outputs. Thereby, the DC potential at the DC input will be indirectly controlled, and it is thus possible to ensure that the potentials with respect to ground at the terminals of the PV modules are all non-negative or all non-positive without grounding the PV modules.