Photovoltaic power plant
AssigneeSMA Solar Technology AG
InventorsUffe Borup, Haase Frerk
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AssigneeSMA Solar Technology AG
InventorsUffe Borup, Haase Frerk
Estimating the term…
In large PV power plants, grounding of individual PV modules may lead to problems. The present invention overcomes such problems. The basis for the invention is a PV power plant comprising one or more PV generators, each comprising a PV string and an inverter with a DC input and an AC output. The PV string comprises at least one PV module and is electrically connected to the DC input of the inverter. The inverter comprises means for controlling the DC potential at the DC input depending on the DC potential at the AC output. The AC outputs of the inverters are coupled in parallel. The novel feature of the invention is that the PV power plant further comprises an offset voltage source, which controls the DC potential at the AC outputs. Thereby, the DC potential at the DC input will be indirectly controlled, and it is thus possible to ensure that the potentials with respect to ground at the terminals of the PV modules are all non-negative or all non-positive without grounding the PV modules. Ground loops can be avoided, and there is no need for the use of transformer-based inverters.
A PV power plant comprising a PV generator, the PV generator comprising a PV string and an inverter with a DC input and an AC output, the PV string comprising at least one PV module and being electrically connected to the DC input, wherein the PV power plant further comprises an offset voltage source, which controls DC potential at the AC outputs, the offset voltage source being connected to an AC side of the inverter between ground and a neutral terminal of the AC output.
A method of controlling a PV power plant, the PV power plant comprising at least one inverter with a DC input electrically connected to a PV string, an AC output and a means for controlling the DC potential at the DC input depending on the DC potential at the AC output, the method comprising that of controlling the DC potential at the AC outputs by use of an offset voltage source connected to an AC side of the at least one inverter between ground and a neutral terminal of the AC output.
Dependencies are inferred from the claim text.