Patent ID: 11888439
Assignee: SMA SOLAR TECHNOLOGY AG
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G  Y | IPC H

Claim 0:
1. A method for determining a characteristic curve for a photovoltaic (PV) string of a PV system having an inverter, which on an input side thereof is connected to the PV string and on an output side thereof is connected to a power supply network,
wherein the PV string comprises a series connection of multiple PV modules, in which at least one of the PV modules is integrated into the series connection of the PV modules via a DC/DC converter,
wherein the DC/DC converter of the at least one of the PV modules is suitable and configured to operate the PV module assigned thereto in a first operating mode M1 by temporal variation of a conversion ratio of output voltage (UOut) to input voltage (UIn) at a maximum power point, and, in a second operating mode M2, to operate the PV module assigned thereto with a temporally constant conversion ratio of output voltage (UOut) to input voltage (UIn),
comprising:
operating the DC/DC converter of the at least one of the PV modules in the second operating mode M2 in response to a current signature for a current (IStr) through the PV string, which current signature is produced by the inverter,
determining a characteristic curve by varying the current 1st or a voltage UStr of the PV string by the inverter and detecting values assigned to one another for current IStr and voltage UStr of the PV string in the second operating mode M2 of the DC/DC converter.