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: In order to be able to perform a shutdown test on an inverter with little expenditure, a trigger signal is modulated to the AC current or the AC voltage at a first moment, and the inverter is used at a second moment, which occurs a defined duration after the start of the trigger signal at the first moment, to generate an AC current or an AC voltage with a fault signal that is detected by the inverter and which triggers a shutdown of the inverter, and the shutdown moment of the AC current or the AC voltage is determined. A shutdown duration of the inverter is determined from the difference between the shutdown moment and the second moment.

Abstract: The invention relates to a method for testing a disconnection point (12) of a photovoltaic inverter (1) and to a photovoltaic inverter (1) of this type. According to the invention, in a testing mode, an auxiliary voltage (U_Lx) is applied between the input (E_Lx) of each line (Lx) of the disconnection point (12) and an intermediate circuit potential (M), in each case, the first switching contacts (SW_Lx,1) are closed and the second switching contacts (SW_Lx,2) are opened alternately and vice versa, according to a switching pattern, and, for each switching pattern, the voltages (U_Lx,GD; U_MN) between the output (A_Lx) of each line (Lx) of the disconnection point (12) and the intermediate circuit potential (M) are measured, and the functionality of each switching contact (SW_Lx,j) is derived from the measured voltages (U_Lx,GD; U_MN).

Abstract: The invention relates to a method for testing a disconnection point (12) of a photovoltaic inverter (1) and to a photovoltaic inverter (1) of this type. According to the invention, in a testing mode, an auxiliary voltage (U_Lx) is applied between the input (E_Lx) of each line (Lx) of the disconnection point (12) and an intermediate circuit potential (M), in each case, the first switching contacts (SW_Lx,1) are closed and the second switching contacts (SW_Lx,2) are opened alternately and vice versa, according to a switching pattern, and, for each switching pattern, the voltages (U_Lx,GD; U_MN) between the output (A_Lx) of each line (Lx) of the disconnection point (12) and the intermediate circuit potential (M) are measured, and the functionality of each switching contact (SW_Lx,j) is derived from the measured voltages (U_Lx,GD; U_MN).

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: A method for feeding energy from photovoltaic modules (2) of a photovoltaic system (1) into a supply grid (5), or to a load, converts the DC voltage (UDC) generated by the photovoltaic modules (2) in an inverter (3) with an intermediate circuit (7) with a capacitor (CZW) and with a DC/AC-converter (8) into an AC voltage (UAC), and in a feed-in mode of operation the inverter (3) is connected via a switching device (4) to the supply grid (5), or to the load, together with an inverter (3) for executing the method. For conservation of the switching device (4) the input power (Pe) of the photovoltaic modules (2) is determined in a test procedure, and the switching device (4) of the inverter (3) is activated if the input power (Pe) of the photovoltaic modules (2) as determined is greater than or equal to a specified minimum input power (Pe,min).

Abstract: Power supply for an inverter and method for operating power supply. Power supply includes a throttle arranged to connect an output end of the inverter to an electric power supply network; a secondary-side auxiliary winding that is arranged on the throttle to transmit an output voltage (UA) of the inverter to a secondary side of the throttle; and a comparator unit. The comparator unit compares a voltage (U1) of the electric supply network with the voltage (U2) of the secondary side of the throttle, to supply, depending upon a result of the comparison of the electric supply network voltage (U1) to the secondary side voltage (U2) of the throttle, electric power to the power supply either from the electric supply network or via the secondary-side auxiliary winding.

Abstract: The invention relates to a method for checking a photovoltaic inverter separator (14) between the photovoltaic inverter (1) and a power supply network (7), comprising multiple phases (L1, L2, L3) and a neutral conductor (N), wherein multiple switching contacts of the separator (14) are controlled by the photovoltaic inverter (1), and the invention also relates to a photovoltaic inverter (1). The aim of the invention is to allow a simple and quick check of the functionality of the separator (14). This is achieved in that the switching contacts of the separator (14) are connected and checked in steps according to a switching pattern. In each step, each voltage (30, 31, 32 and 33, 34, 35) is measured at at least one phase (L1, L2, L3) upstream and downstream of the separator (14) in relation to the neutral conductor (N), and the voltages are compared to one another.

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: A method for feeding energy from photovoltaic modules (2) of a photovoltaic system (1) into a supply grid (5), or to a load, converts the DC voltage (UDC) generated by the photovoltaic modules (2) in an inverter (3) with an intermediate circuit (7) with a capacitor (CZW) and with a DC/AC-converter (8) into an AC voltage (UAC), and in a feed-in mode of operation the inverter (3) is connected via a switching device (4) to the supply grid (5), or to the load, together with an inverter (3) for executing the method. For conservation of the switching device (4) the input power (Pe) of the photovoltaic modules (2) is determined in a test procedure, and the switching device (4) of the inverter (3) is activated if the input power (Pe) of the photovoltaic modules (2) as determined is greater than or equal to a specified minimum input power (Pe,min).

Abstract: To be able to maintain the power supply of an inverter which is supplied with power from a supply network even in the event of a power failure, it is proposed according to the invention that in the event of a power failure, the electric power for the power supply (2) of the inverter (1) is obtained from a throttle (7) of the inverter (1) at the output end via an auxiliary winding (13).

Abstract: The invention relates to a method for checking a photovoltaic inverter separator (14) between the photovoltaic inverter (1) and a power supply network (7), comprising multiple phases (L1, L2, L3) and a neutral conductor (N), wherein multiple switching contacts of the separator (14) are controlled by the photovoltaic inverter (1), and the invention also relates to a photovoltaic inverter (1). The aim of the invention is to allow a simple and quick check of the functionality of the separator (14). This is achieved in that the switching contacts of the separator (14) are connected and checked in steps according to a switching pattern. In each step, each voltage (30, 31, 32 and 33, 34, 35) is measured at at least one phase (L1, L2, L3) upstream and downstream of the separator (14) in relation to the neutral conductor (N), and the voltages are compared to one another.

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 photovoltaic plant having a plurality of inverters (1) connected to each other by way of a network (12), wherein the inverters (1) comprise a control apparatus (7) having at least one microprocessor (8) and at least one storage, an interface for communicating with the remaining inverters (1), a DC/AC module (3) for converting a direct current supplied from an external energy source into an alternating current, and an input/output unit (9), and to such an inverter (1) and a USB mass storage device (11), as well as to a method for carrying out software updates. According to the invention, a USB interface (10) is arranged on at least one inverter (1) for connecting a USB mass storage device (11), in particular a USB stick, so as to carry out automatic updates in a software running in the microprocessor (8) and/or configuration block updates and/or so as to record logging data of the inverters.

Abstract: The invention relates to a photovoltaic plant having a plurality of inverters (1) connected to each other by way of a network (12), wherein the inverters (1) comprise a control apparatus (7) having at least one microprocessor (8) and at least one storage, an interface for communicating with the remaining inverters (1), a DC/AC module (3) for converting a direct current supplied from an external energy source into an alternating current, and an input/output unit (9), and to such an inverter (1) and a USB mass storage device (11), as well as to a method for carrying out software updates. According to the invention, a USB interface (10) is arranged on at least one inverter (1) for connecting a USB mass storage device (11), in particular a USB stick, so as to carry out automatic updates in a software running in the microprocessor (8) and/or configuration block updates and/or so as to record logging data of the inverters.