Method and device for recognizing faults in a photovoltaic system

摘要

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.

主权项

1. A method for recognizing faults in a photovoltaic system, comprising the steps:
determining a first parameter derived from a first output voltage of the photovoltaic system at a first time point in a first operating state of the photovoltaic-system for determining a starting condition during an initialization process, determining a second parameter derived from a second output voltage of the photovoltaic system at a second time point, when a weather analysis for establishing a sun radiation above a threshold leads to a positive result and there is a second operating state comparable with the first operating state, wherein the weather analysis is performed by using output data from the inverter and without using a light sensitive sensor or a radiation sensor, and wherein the weather analysis is considered to be positive if a power output of the inverter is above 15% of the respective nominal power, determining a deviation between the first and second parameter and outputting an error message when the deviation exceeds a predeterminable threshold, wherein each of the first parameter and the second parameter is the ratio between the maximum power point voltage and the open circuit voltage of the photovoltaic system.