Abstract: Method for optimizing a maximum power point of a solar cell stack having modules, each including an MLSD unit, and an inverter. The MLSD unit shuts down the module when module voltage falls below a first voltage threshold, and switches it on, when a predefined second voltage threshold is exceeded. For optimal performance, the solar cell stack carries out: Defining, changing an electrical control parameter to a first wait value so that the second voltage threshold is exceeded exceeded; maintaining first wait value for a first time period so the modules are switched on by the MLSD units; changing electrical control parameter to a threshold value in a variation range and determining current-voltage curves for the modules in variation range; determining maximum stack power from current-voltage curves of the modules in the variation range; and predefining the determined maximum stack power as the maximum performance point.

Abstract: An electronic assembly includes at least one circuit board and external electronic components including electrical connections, wherein the circuit board has contacts for connection to the connections of the external electronic components, and the at least one circuit board and the external components are able to be attached to a housing part. Also, an inverter includes a power unit. A carrier which is mounted so as to be able to be moved is provided on the housing part, wherein the carrier has holders for receiving contact elements for connection to the connections of the external electronic components and for connection to the contacts on the circuit board.

Abstract: To determine an AC insulation resistance between the AC connections of an inverter and a ground potential, the AC connections are connected to an AC energy sink in an emergency standby operation in order to transmit energy from a DC energy source to an AC energy sink and an insulation test is performed in emergency standby operation. An AC fault current flowing between an AC connection and the ground potential is determined, and the AC insulation resistance is calculated from the AC fault current.

Abstract: A choke includes at least one winding each having two connections, and a magnetic core having an air gap, wherein a coil body made up of at least two parts is provided for receiving the at least one winding, and a base plate that can be connected to the coil body is also provided. The at least two parts of the coil body and the base plate include first latching elements and second latching elements for tool-free connecting the at least two parts of the coil body and for tool-free connecting the base plate to the coil body, and the magnetic core is built up from sheets stacked one on top of the other, and the base plate is designed to receive the sheets of the magnetic core.

Abstract: In a method for operating an inverter assembly and inverter assembly for carrying out the method, to reduce the risk of triggering a ground fault circuit interrupter, before feeding in the alternating voltage, the leakage capacitance to ground is determined at the DC input of each inverter, and which AC output is connected to which line of the supply network is determined, and, taking into consideration the leakage capacitance and a defined maximum leakage current and the connection situation at the AC output, the power units are asymmetrically modulated so that the amplitudes of the voltages at the AC outputs of the power units differ in size. The voltage with the greater amplitude comes about at the AC output of this power unit connected to the phase connection. The voltage with the lower amplitude comes about at the AC output of the power unit connected to the neutral conductor.

Abstract: To improve voltage balancing at the DC link capacitor voltages of a multi-level inverter with a split DC link a modulation signal with a modulation signal amplitude as even harmonic signal of the output voltage or output current of the inverter is calculated from an actual electric power difference of the actual electric powers at the DC link capacitors and is superimposed onto the setpoint value for setting an output voltage or output current of the inverter.

Abstract: In order to provide an improved method for producing metal structures which allows a high level of flexibility in respect of process speed of production, material composition of the metal structure, production accuracy, and the quality of the produced metal structure, according to the invention, a second metal additive is supplied to a welding point on a metal base material, which second metal additive is fused at least by a second electric arc produced between a second electrode and the metal base material in order to produce a second weld seam at the welding point, wherein different materials are used as the first metal additive and as the second metal additive, and wherein the first metal additive and the second metal additive are supplied to the welding point sequentially in time and are fused in the region of the welding point in whichever of the first and second electric arcs is burning, in order to form the three-dimensional metal structure.

Abstract: In a method and a carrier gas nozzle for allowing at least one fluid to flow over a welding area of a workpiece along a welding path during a welding process, the at least one fluid is flowed onto the welding area via at least one inlet and channels having openings. The openings of the channels are divided into at least two sectors, and at least one flow parameter, if need be also a property of the at least one fluid of each sector, is individually controlled, wherein at least one flow parameter of at least one fluid of at least one sector is controlled depending on the geometry of the welding path and/or depending on the geometry of the workpiece.

Abstract: In a method and device for assessing the quality of a processing operation, a workpiece with specific processing parameters is processed along a processing trajectory. The (X), wherein the processing result is measured by at least one sensor and at least one sensor signal is recorded and at least one quality parameter is determined based on at least one sensor signal and the at least one quality parameter is compared with quality parameter threshold values to assess the quality of the processing result. During the assessment of the processing operation quality, changes made to the processing parameters from target values during the processing are automatically taken into consideration, in that, instead of the quality parameter threshold values, quality parameter threshold values adapted to the changes in the processing parameters are determined, and the at least one quality parameter for assessing the quality of the processing result is compared with the adapted quality parameter threshold values.

Abstract: A choke includes at least one winding each having two connections, and a magnetic core having an air gap, wherein a coil body made up of at least two parts is provided for receiving the at least one winding, and a base plate that can be connected to the coil body is also provided. The at least two parts of the coil body and the base plate include first latching elements and second latching elements for tool-free connecting the at least two parts of the coil body and for tool-free connecting the base plate to the coil body, and the magnetic core is built up from sheets stacked one on top of the other, and the base plate is designed to receive the sheets of the magnetic core.

Abstract: To allow reliable current measurement of the output current of the switching stage of an inverter, especially at switching frequencies of the semiconductor switches in the 100 kHz range, a voltage at the choke is measured and integrated over time to be representative for the leg current in the choke. The time integral is processed in a processing unit, whereas the processed time integral is used in an inverter controller for controlling the inverter. The voltage at the choke is analogously integrated over time by two serially connected integrator capacitors, whereas across each of the integrator capacitors a reset switch is provided, for alternately resetting the corresponding integrator capacitor.

Abstract: The aim of the invention is to detect an arc in an assembly for transmitting a direct voltage. This aim is achieved by a communication transformer having a primary winding and a secondary winding, the secondary winding being connected to a transmitting device, which is designed to impress a communication signal onto the secondary winding of the communication transformer, and the primary winding being connected to one of the direct voltage lines in order to feed a communication signal transformed by the communication transformer to one of the direct voltage lines. In order to detect, in the assembly, the arc signal caused by an arc, the secondary winding is connected to an arc detection unit, which is designed to detect an arc signal transformed by the communication transformer.

Abstract: In a method for operating an inverter assembly and inverter assembly for carrying out the method, to reduce the risk of triggering a ground fault circuit interrupter, before feeding in the alternating voltage, the leakage capacitance to ground is determined at the DC input of each inverter, and which AC output is connected to which line of the supply network is determined, and, taking into consideration the leakage capacitance and a defined maximum leakage current and the connection situation at the AC output, the power units are asymmetrically modulated so that the amplitudes of the voltages at the AC outputs of the power units differ in size. The voltage with the greater amplitude comes about at the AC output of this power unit connected to the phase connection. The voltage with the lower amplitude comes about at the AC output of the power unit connected to the neutral conductor.

Abstract: A cooling device for cooling power electronics components arranged in a housing includes a heat sink and a fan having an electric motor with a rotor and rotor blades connected to the rotor in a torque-proof manner, wherein the motor is arranged in a motor housing and is connected to a cable, and the heat sink has cooling fins and a cavity for receiving the fan, wherein a recess, which is designed for receiving the motor housing of the fan is arranged in the cavity of the heat sink. The motor housing of the fan has a peripheral seal and the cable and a fastening element are arranged on the side of the motor housing facing away from the rotor blades, wherein a receptacle for the fastening element and a feed-through for the cable are arranged in the recess.

Abstract: A secure, reliable and simplified control mechanism for operating an inverter is provided. In particular, a mechanical switch is used for connecting a local grid with a public grid and for disconnecting the local grid from the public grid. The mechanical switch comprises an intermediate position. Each time when the switch is in this intermediate position, the inverter is immediately shut down in a fast shutdown operation.

Abstract: In a method in which a welding process is carried out on a workpiece with a welding torch and to a welding device for carrying out the method, a welding current source is supplied in order to provide a welding voltage, and an electrical voltage is applied, at least temporarily, during the welding process to an external element of the welding torch, in particular to an outer wall of a gas nozzle, and a possibly occurring electrical contact between the external element and a further element, in particular the workpiece or a contact tube, is detected by the electrical voltage applied. The welding current source is electrically connected via at least one first resistor to the external element of the welding torch and the external element of the welding torch is connected to the electrical potential of the workpiece via at least one second resistor.

Abstract: A a multiple welding method having an improved starting process in which the control unit of the guide electrode starts welding-wire advancing of the guide electrode and sends a synchronization signal to the control unit of the trailing electrode when the guide electrode has moved a certain distance or for a certain time. The control unit of the trailing electrode starts welding-wire advancing of the trailing electrode in dependence on the received synchronization signal before the guide electrode touches the workpiece.

Abstract: An electronic assembly includes at least one circuit board and external electronic components including electrical connections, wherein the circuit board has contacts for connection to the connections of the external electronic components, and the at least one circuit board and the external components are able to be attached to a housing part. Also, an inverter includes a power unit. A carrier which is mounted so as to be able to be moved is provided on the housing part, wherein the carrier has holders for receiving contact elements for connection to the connections of the external electronic components and for connection to the contacts on the circuit board.

Abstract: In order to achieve improved single-phase operation of an inverter having a first input pole and a second input pole and including at least three phase branches, each having at least one upper power switch and at least one lower power switch connected in series to the at least one upper power switch via an output pole, a switching unit is provided. The switching unit is designed to switch the inverter from multi-phase operation to single-phase operation by closing a center point connection switch in order to connect the third output pole to the DC link center point. The switching unit is further designed, in single-phase operation, to effect a control of the upper and lower power switch of the third phase branch for symmetrizing the DC link voltages at the first and second DC link capacitors.

Abstract: In order to protect an inverter from prohibited switching states, a monitor including monitoring inputs and monitoring outputs is provided. The monitoring inputs are connected to the control outputs in order to receive the switching patterns, and the monitoring outputs are connected to the power switches. The monitor is designed to compare a transition from a first switching pattern to a second switching pattern with a number of prohibited transitions and/or with a number of permitted transitions and block the second switching pattern in the event of a match with one of the prohibited transitions and/or in the event of a deviation from the number of permitted transitions and to output the second switching pattern to the power switches via the monitoring outputs in the event of a deviation from the number of prohibited transitions and/or in the event of a match with one of the permitted transitions.