Abstract: An inverter includes a DC/DC converter which converts a direct current received from a DC voltage source into an intermediate circuit voltage of an intermediate circuit, a DC/AC converter which converts the intermediate circuit voltage into an AC voltage, and a monitoring unit which monitors capacitors of the intermediate circuit for protection against overvoltages. If an overvoltage occurs at one of the capacitors of the intermediate circuit the overvoltage unit decouples the DC voltage source from the intermediate circuit by actuating the DC/DC converter.

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: Inverter (1) comprising a DC/DC converter (4) which converts a direct current received from a DC voltage source (3) into an intermediate circuit voltage of an intermediate circuit (5), a DC/AC converter (6) which converts the intermediate circuit voltage into an AC voltage, and comprising a monitoring unit (8) which monitors capacitors of the intermediate circuit (5) for protection against overvoltages, the over-voltage unit (8), if an overvoltage occurs at at least one of the capacitors of the intermediate circuit (5), decoupling the DC voltage source (3) from the intermediate circuit (5) by actuating the DC/DC converter (4).

Abstract: Method and device for determining an insulation resistance RISO of a photovoltaic system (1) with respect to earth potential (EP), comprising a DC-DC converter unit (4) which converts a first DC voltage generated by the photovoltaic generator (2) into a second DC voltage which is applied to an intermediate circuit (5) that temporarily stores the electrical energy, supplied by the photovoltaic generator (2), for a DC-AC converter unit (6) connected thereto, wherein the intermediate circuit (5) contains a reference node (BK) having an adjustable reference potential (BP), and comprising a measuring unit (7) which picks up the measuring voltages between the reference potential (BP) and the earth potential (EP) at different reference potentials (BP), and an evaluation unit (8) which evaluates the measuring voltages that have been picked up in order to determine the insulation resistance of the photovoltaic generator (2) of the photovoltaic system (1).

Abstract: The invention relates to a method for checking a separation point (14) between a photovoltaic inverter (1) and a power supply network (7) having multiple phases (L1, L2, L3) and a neutral conductor (N), wherein multiple switching contacts of the separation point (14) are controlled by the photovoltaic inverter (1), and to a photovoltaic inverter (1). To allow a simple and quick check of the functionality of the separation point (14), the switching contacts of the separation point (14) are each formed by single-pole relays (15-22) and switched in steps according to a switching pattern. For checking switching contacts, a voltage (26, 27, 28) is measured at at least one phase (L1, L2, L3) with respect to the neutral conductor (N), upstream of the separation point (14), and compared to voltage values assigned in accordance with the switching pattern, thereby to deduce the functionality of the switching contacts.

Abstract: Method and device for determining an insulation resistance RISO of a photovoltaic system (1) with respect to earth potential (EP), comprising a DC-DC converter unit (4) which converts a first DC voltage generated by the photovoltaic generator (2) into a second DC voltage which is applied to an intermediate circuit (5) that temporarily stores the electrical energy, supplied by the photovoltaic generator (2), for a DC-AC converter unit (6) connected thereto, wherein the intermediate circuit (5) contains a reference node (BK) having an adjustable reference potential (BP), and comprising a measuring unit (7) which picks up the measuring voltages between the reference potential (BP) and the earth potential (EP) at different reference potentials (BP), and an evaluation unit (8) which evaluates the measuring voltages that have been picked up in order to determine the insulation resistance of the photovoltaic generator (2) of the photovoltaic system (1).

Abstract: The invention relates to a method for checking a separation point (14) between a photovoltaic inverter (1) and a power supply network (7) having multiple phases (L1, L2, L3) and a neutral conductor (N), wherein multiple switching contacts of the separation point (14) are controlled by the photovoltaic inverter (1), and to a photovoltaic inverter (1). To allow a simple and quick check of the functionality of the separation point (14), the switching contacts of the separation point (14) are each formed by single-pole relays (15-22) and switched in steps according to a switching pattern. For checking switching contacts, a voltage (26, 27, 28) is measured at at least one phase (L1, L2, L3) with respect to the neutral conductor (N), upstream of the separation point (14), and compared to voltage values assigned in accordance with the switching pattern, thereby to deduce the functionality of the switching contacts.

Abstract: The invention relates to a method for detecting arcs in a direct-current path of a photovoltaic system, wherein values of a current (IDC) of the direct-current path are detected during a repeating time frame (7) and a mean value (8) is generated, and such a photovoltaic system. In order to reliably detect arcs by means of a component of the photovoltaic system, values of a voltage (UDC), of the direct-current path are detected during the time frame (7) and a mean value (8, 8?) is generated, and at least one detection signal (9) and at least one detection threshold (10) are continuously calculated based on the mean values (8, 8?) for the current (IDC) and the voltage (UDC) by means of a calculation method.

Abstract: The invention relates to a method for detecting arcs in a direct-current path of a photovoltaic system, wherein values of a current (IDC) of the direct-current path are detected during a repeating time frame (7) and a mean value (8) is generated, and such a photovoltaic system. In order to reliably detect arcs by means of a component of the photovoltaic system, values of a voltage (UDC), of the direct-current path are detected during the time frame (7) and a mean value (8, 8?) is generated, and at least one detection signal (9) and at least one detection threshold (10) are continuously calculated based on the mean values (8, 8?) for the current (IDC) and the voltage (UDC) by means of a calculation method.

Abstract: An adjustment aid (29) for a component of a welding device (1) in the form of an element for mounting or fastening on an input and/or output unit (18) of the component, on which element additionally information (31) and/or scale (32) for adjusting a welding process are printed is provided. In order to simplify the adjustment of a certain welding process by the user, it is provided that the element is formed by a flexible element or foil (30) with two openings (33) for mounting or fastening on two rotary knobs (34) of the input and/or output unit (18), the openings each having a first part (38) and a second part (39), wherein the first part (38) of each opening (33) is designed for guiding through a rotary knob (34) and the second part (39) of each opening (33) is formed for fixation between the two rotational axes (37) of the rotatory knobs (34).

Abstract: The invention relates to a device for protecting the housing (26) of a welding component while changing the position thereof, wherein a drag protection (27) in the form of a plate (28) is provided for fastening and for protecting the housing (26), which plate (28) is provided on an outer side (29) with elevations (30) for reducing a bearing surface and a friction resistance.

Abstract: The invention relates to a method of transmitting data between and/or synchronising at least two welding devices (1, 27) or current sources or with another component and another device, which are supplied with energy via a supply network (35), whereby the functions of the welding process are controlled and/or regulated by means of a control system (4, 30) of the welding device (1, 27). The data, signals and welding parameters or synchronisation signals to be transmitted from a welding device (1, 27) or a welding current source or another component and another device, in particular by a processor, a PLC controller, a data module or a computer, etc., are converted by means of a communication unit (36, 37) into a data protocol which is then modulated by a communication unit (36, 37), in particular a modulation module (42, 43), across the supply network (35).

Abstract: The invention relates to a method of linking several current sources, in particular several welding devices (1; 27; 28), plasma current sources or similar. Operating individually and independently of one another, a process control and/or regulating system (4; 31; 32) in every welding device (1; 27; 28) transmits desired values to a voltage-to-current controller of a power component (3; 29; 30). The power component (3; 29; 30) supplies a consumer connected to output jacks (38, 39; 40, 41; 42, 43) with power on the basis of the desired values.

Abstract: The invention relates to a method of linking several current sources, in particular several welding devices (1; 27; 28), plasma current sources or similar. Operating individually and independently of one another, a process control and/or regulating system (4; 31; 32) in every welding device (1; 27; 28) transmits desired values to a voltage-to-current controller of a power component (3; 29; 30). The power component (3; 29; 30) supplies a consumer connected to output jacks (38, 39; 40, 41; 42, 43) with power on the basis of the desired values.

Abstract: The invention describes a method of operating a data exchange between an external component, in particular a remote control unit (23), and a welding unit (1), in particular a current source. A serial data exchange is run between a welding unit (1), in particular a current source, and an external component, in particular a remote control unit (23), directly across the welding lines, in particular across the connecting lines (36) to the welding torch (10) and to the workpiece (16), on the basis of digital levels.