Patent ID: 8743570

Claim:
An apparatus for converting DC voltage from an electrochemical storage device or a fuel cell into an AC voltage for feeding into a power grid, comprising: a single DC-to-DC converter stage configured to generate an intermediate circuit voltage from an output voltage of the storage device or the fuel cell, wherein the single DC-to-DC converter stage is configured to convert a DC voltage in a wide input voltage range to the intermediate circuit voltage, with which a single DC-to-AC converter stage configured to generate the AC voltage can be operated, wherein the single DC-to-DC converter stage comprises two or more DC-to-DC converter devices connected together in parallel between the storage device or the fuel cell and the DC-to-AC converter stage, and a control device configured to drive the two or more DC-to-DC converter devices individually and differently from one another with control parameters that depend on an input voltage of the single DC-to-DC converter stage, wherein the control parameters comprise a clock frequency of a driving signal for driving switches of the DC-to-DC converter devices and a duty cycle of the driving signal, wherein the DC-to-AC converter stage is configured to generate the AC voltage from the intermediate circuit voltage.