Method for activating a multi-string inverter for photovoltaic plants
First Claim
1. A method of controlling a Multi-String inverter for a plurality of photovoltaic generator strings of a photovoltaic plant, said Multi-String inverter incorporating one separate DC-DC converter for each photovoltaic generator string on its input side, each output of said DC-DC converters being connected in parallel and with an input of a DC-AC converter and said DC-AC converter being configured to be connected to an alternating current mains for feeding into the mains, comprising:
- measuring an input current, input voltage and/or input power at each DC-DC converter, thereby generating measured input parameters; and
changing an operating condition of at least one of the DC-DC converters based upon a comparison of the measured input parameters of at least two of the DC-DC converters.
1 Assignment
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Accused Products
Abstract
A method of activating a Multi-String inverter for photovoltaic generators (1a, 1b) of a photovoltaic plant (6), the Multi-String inverter incorporating on the input side a separate DC-DC converter (2a, 2b) for each generator string (photovoltaic generator) (1a, 1b) and each output of the DC-DC converters (2a, 2b) being connected in parallel and to an input of a DC-AC converter (3) and the DC-AC converter (3) being connected with an alternating current mains (4) for feeding into the mains aims at improving efficiency. This is achieved in that one or several electrical variables, namely input current, input voltage and/or input power are measured at each DC-DC converter (2a, 2b) and at least one of the DC-DC converters (2a, 2b) changing its operating condition as a function of this measurement when a limit value and/or a range is exceeded in such a manner that its power loss is reduced so that the energy yield of the photovoltaic plant (6) is increased.
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Citations
25 Claims
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1. A method of controlling a Multi-String inverter for a plurality of photovoltaic generator strings of a photovoltaic plant, said Multi-String inverter incorporating one separate DC-DC converter for each photovoltaic generator string on its input side, each output of said DC-DC converters being connected in parallel and with an input of a DC-AC converter and said DC-AC converter being configured to be connected to an alternating current mains for feeding into the mains, comprising:
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measuring an input current, input voltage and/or input power at each DC-DC converter, thereby generating measured input parameters; and changing an operating condition of at least one of the DC-DC converters based upon a comparison of the measured input parameters of at least two of the DC-DC converters. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An inverter, comprising:
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a plurality of DC-DC converters, each of the DC-DC converters comprising a pair of input terminals configured to couple to a photovoltaic module, and a pair of output terminals coupled together in parallel to form a single pair of DC-DC converter output terminals; a DC-AC converter having a pair of input terminals coupled to the single pair of DC-DC converter output terminals, and having a pair of output terminals configured to couple to a grid; and a controller configured to selectively control one or more of the DC-DC converters based on input voltages at the input terminals of at least two of the DC-DC converters and a grid voltage at the output terminals of the DC-AC converter. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. An inverter, comprising:
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a plurality of DC-DC converters, each of the DC-DC converters comprising a pair of input terminals configured to couple to a photovoltaic module, and a pair of output terminals coupled together in parallel to an intermediate circuit; a DC-AC converter having a pair of input terminals coupled to the intermediate circuit, and having a pair of output terminals configured to couple to a grid; and a controller for controlling at least a first DC-DC converter of the plurality of DC-DC converters, wherein the controller is configured to deactivate a first DC-DC converter when a first voltage at the input terminals of the first DC-DC converter exceeds a peak voltage of the grid and the first voltage exceeds voltages at the input terminals of each other of the plurality of DC-DC converters. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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Specification