Abstract: The invention relates to a method and a device for recognizing faults in a photovoltaic system (1). A first output voltage (U0, UMPP) of the system (1) and/or a first parameter derived from the output voltage (U0, UMPP) is determined at a first point in time in a first operating state of the photovoltaic system (1). At a second point in time in a second operating state comparable to the first operating state, a second output voltage (U0, UMPP) and/or a second parameter of the system (1) derived from the output voltage (U0, UMPP) is determined. Finally, a deviation between the first and the second output voltage (U0, UMPP) and/or between the first and the second parameter is identified and a fault notification is output if the deviation exceeds a predeterminable threshold.

Abstract: The invention relates to a method for recognition of the theft of at least one solar module (5) on a photovoltaic unit with an inverter (1) an intermediate circuit (3), a DC-AC converter (4), at least one solar module (5) connected via connector lines (19) and a control device (8). A signal unit (19) which can be connected to the connector lines (9, 10), for generating and transmitting an electrical signal and a device for measuring and analyzing the signal received from the at least one solar module (5) are provided such that conclusions can be drawn about the theft of a solar module (5) from the received signal. According to the invention, reliable recognition of theft of a solar module (5) can be achieved by designing the signal unit (19) for generating varying electrical signals.

Abstract: The invention relates to a method and a device for recognizing faults in a photovoltaic system (1). A first output voltage (U0, UMPP) of the system (1) and/or a first parameter derived from the output voltage (U0, UMPP) is determined at a first point in time in a first operating state of the photovoltaic system (1). At a second point in time in a second operating state comparable to the first operating state, a second output voltage (U0, UMPP) and/or a second parameter of the system (1) derived from the output voltage (U0, UMPP) is determined. Finally, a deviation between the first and the second output voltage (U0, UMPP) and/or between the first and the second parameter is identified and a fault notification is output if the deviation exceeds a predeterminable threshold.

Abstract: The invention relates to a method for recognition of the theft of at least one solar module (5) on a photovoltaic unit with an inverter (1) an intermediate circuit (3), a DC-AC converter (4), at least one solar module (5) connected via connector lines (19) and a control device (8). A signal unit (19) which can be connected to the connector lines (9, 10), for generating and transmitting an electrical signal and a device for measuring and analyzing the signal received from the at least one solar module (5) are provided such that conclusions can be drawn about the theft of a solar module (5) from the received signal. According to the invention, reliable recognition of theft of a solar module (5) can be achieved by designing the signal unit (19) for generating varying electrical signals.