Abstract: A method for limiting an output power of an inverter having an output bridge and an upstream boost converter includes determining a first measurement variable representative of a bridge temperature and a second measurement variable representative of an output power of the inverter. The method also includes determining a third measurement variable representative of a generator voltage at generator connections of the inverter or a fourth measurement variable representative of an output voltage at a power output of the inverter, and reducing the output power supplied to a power supply grid to a reduced power value. The reduced power value is determined based on the first measurement variable, the second measurement variable and at least one of the third and fourth measurement variables. A control device having such functionality is also disclosed.

Abstract: The invention relates to an inverter with at least one DC input for connecting to an energy producing device and/or an energy store and with a multiphase AC output for connecting to a local energy distribution network, which is coupled to a likewise multiphase master energy supply network via a switching device.

Abstract: A disconnect unit and an associated method in a photovoltaic system includes a plurality of input power lines configured to receive power from a photovoltaic (PV) generator, and deliver the received power to an inverter. The disconnect unit further includes a sensor configured to determine a voltage at the plurality of input power lines, and a controller configured to selectively disconnect and reconnect one or more of the plurality of input power lines based on the determined voltage.

Abstract: The method of detecting an arc fault in a power circuit includes determining a first signal related to current flowing in the power circuit is determined and analyzing the first signal to determine whether the signal indicates the presence of an electric arc in the power circuit. In case the first signal indicates the presence of an electric arc in the power circuit, means for suppressing an electric arc are activated. A second signal related to current flowing in the power circuit is then determined and analyzed. An occurrence of an arc fault in the power circuit is signaled if the second signal does not indicate the presence of an electric arc. The system for detecting an arc fault is designed to perform a corresponding method.

Abstract: A method of communication of distributed devices handling electric energy with communication partners via the Internet includes programming rules in a server. The rules determine between which device and which communication partner a communication connection is to be mediated based on generic properties of the devices, generic properties of the communication partners and an initializing time-variable datum. The communication connection is a point to point, point to multi point or multi point to multi point connection via the internet. Data are transmitted from each device and each communication partner to the server via the Internet. These data include both a communication address and attributes indicative of the generic properties of the device or the communication partner, respectively. The communication connection is mediated between the device and the communication partner determined by the rules in response to a value of the initializing time-variable datum also defined by the rules.

Abstract: A circuitry includes first, second, and third switching elements, first and second storage inductors, two connector pairs, and first and second intermediate potential points. The second storage inductor includes first and second windings. The first intermediate potential point is connected to a first connector of the first connector pair via the first storage inductor, to the second connector of the first connector pair via the third switching element, and to the second intermediate potential point. The second intermediate potential point is connected to the first connector of the second connector pair via a series connection of the first switching element and the first winding of the second storage inductor, and to the second connector of the second connector pair via a series connection of the second switching element and the second winding of the second storage inductor.

Abstract: A power inverter includes two input terminals, two output terminals and a resonant converter that includes a high frequency transformer having a primary winding and a secondary winding, at least one high frequency switched semiconductor power switch that connects one end of the primary winding of the high frequency transformer to one of the input terminals to provide a current path through the primary winding to the other one of the input terminals. The power inverter further includes a resonant series circuit having an inductance and a capacitance, and a high frequency rectifier that rectifies a current through the secondary winding, two output lines, and an output converter connected between the output lines of the high frequency rectifier and the two output terminals.

Abstract: For recognizing shadowing events affecting a photovoltaic module, electric power produced by the module is recorded. For each position of the sun on a present day an expected value of the electric power is defined. Further, an ideal power course of the electric power over the present day is determined by fitting a curve that corresponds to cloudless sun without shadow casting obstacles to peak values of the electric power recorded for same positions of the sun during a plurality of previous days. For all positions of the sun at which the electric power produced on the present day falls short of the ideal power course a shadowing probability of not less than zero is defined whose magnitude depends on the level of accord of the electric power produced on the present day with the expected value at the position of the sun.

Abstract: A method for grid support by means of an inverter is disclosed, wherein the grid is supported by feeding in compensation currents. The method includes measuring a prevailing grid state, and breaking down voltages measured for measuring the prevailing grid state into symmetrical components of the grid state including positive sequence system components and negative sequence system components. The method further includes determining symmetrical components of a compensation current including positive sequence system components and negative sequence system components of the compensation current as functions of deviations of the positive sequence system components and negative sequence system components of the grid state from reference values, and feeding-in a compensation current as the vector sum of the determined symmetrical components of the compensation current.

Abstract: The disclosure relates to an electrical connection between two busbars made of flat conductors and an insulating layer disposed between the conductors at the opposite longitudinal edges of the two busbars. The two conductors of each busbar run parallel to each other at a distance on the longitudinal edge thereof, wherein a molded part made of electrically insulating material bridges the distances between the conductors of the two busbars. Electrically conductive contact elements, forced against each other but electrically insulated from each other, each contact one of the conductors of each busbar by means of structured contact surfaces and clamp the same between the element and the molded part, wherein the contact surfaces for the conductors of the two busbars including clamping protrusions running parallel to the longitudinal edges.

Abstract: A system for closed-circuit power line communication includes at least a first and second power line connected to at least one electrical device configured to receive a data signal. An auxiliary line is connected to the electrical devices to provide a ground connection, and at least one transmitter generates a first data signal for transmission over the first and second power lines, respectively, to the electrical device. A low-pass common-mode filter is connected to the first and second power lines to provide closed-circuit data communication between the transmitter and the electrical device, the filter comprising at least one coupling capacitor between said first and second power lines such that at least the polarities with respect to ground of said first data signals transmitted over the first and second power lines, respectively, are substantially similar.

Abstract: A transformerless inverter that serves to feed electricity from a DC current source into an AC power grid, has an inverter bridge and a DC/DC converter connected upstream of the inverter bridge. The DC/DC converter converts an input DC voltage that is present between two input lines of the inverter into a DC link voltage present between two input lines of the inverter bridge. The inverter bridge converts the DC link voltage present at the input lines thereof into an output AC voltage. The DC/DC converter includes at least one resonant circuit that has a resonance inductance and a resonance capacitance and is connected on its input side via at least two clocked switches to one of the two input lines of the inverter or an intermediate potential line carrying a potential in between. The input lines of the inverter and the input lines of the inverter bridge are galvanically isolated from one another by a capacitive method.

Abstract: The invention relates to an inverter with an enclosure that includes a removable hand plug which, when inserted inside the enclosure, shares an electrical connection with the inverter. The hand plug includes a fan configured to cool at least a portion of the inverter enclosure.

Abstract: A method of building a wireless communication network between a plurality of pre-defined devices which include spatially distributed inverters for feeding electric energy into an AC power grid and which each have a spatially limited range in wireless communication is provided. The method includes the steps of assimilating the pre-defined devices for a limited period of time, and in the step of assimilating, generating at least one network ID and persistently storing the at least one network ID in each pre-defined device participating in the step of assimilating. The method further includes, after the step of assimilating, connecting each pre-defined device exclusively to such other pre-defined devices in which network IDs originating from the same step of assimilating are stored.

Abstract: During startup of a DC/DC converter having a high-frequency transformer whose primary winding is supplied with current from an input-side DC link via an inverter bridge having pulsed switches and whose secondary winding is used to charge an output-side DC link via a rectifier bridge. The switches of the inverter bridge are operated to load the output-side DC link, in a manner that deviates from a normal operation of the switches in order to limit the currents that flow in the DC/DC converter during startup of the DC/DC converter. Particularly, the switches of the inverter bridge are operated during startup of the DC/DC converter at a pulse width that is fixed during each of a limited number of stages of the startup, and have a duty cycle that is not more than 5 percent during each of the stages of the startup.

Abstract: A method for detecting an arc fault in a photovoltaic power circuit includes operating a photovoltaic generator at a first working point. A first signal related to a DC-current and/or a DC-voltage in the power circuit is determined. The first signal is analyzed and it is determined whether the signal indicates the presence of an electric arc in the power circuit. If so, the photovoltaic generator is operated at a second working point and a second signal related to the DC-current and/or the DC-voltage is determined. The first and second signals are then compared; and the occurrence of an arc fault in the power circuit is selectively signaled based on the comparison.

Abstract: The invention relates to a photovoltaic system for feeding three-phase current to a power grid that includes several monophase or three-phase photovoltaic inverters that can be connected to the power grid at the output end and are each fitted with a disconnecting device at the output end. The system includes several photovoltaic generators that are connected to the input end of the photovoltaic inverters. A central control and monitoring unit is connected between the photovoltaic inverters and the power grid. The control and monitoring unit has a grid monitoring device at the feeding point to the grid to measure one or more grid parameters. At least one communication link is provided between the individual photovoltaic inverters or the individual disconnecting devices and the connected central control and monitoring unit such that the connecting devices can disconnect the individual photovoltaic inverters from the power grid by means of a control instruction signal of the communication link.

Abstract: On an inverter (1) for converting an electric direct voltage, in particular of a photovoltaic direct voltage source into an alternating voltage with a direct voltage input with two terminals (DC+, DC?) and one alternating voltage output with two terminals (AC1, AC2) and with one bridge circuit including semiconductor switching elements (S1-S6), said bridge circuit comprising one first bridge branch (Z1) including four switching elements (S1-S4) and one second bridge branch (Z2) including two additional switching elements (S5, S6) as well as a freewheeling circuit provided with additional diodes (D7, D8), the efficiency is further increased without high frequency interferences and capacitive leakage currents having the possibility to occur on the generator side.