Patent ID: 7944091

Claim:
An apparatus for feeding electrical energy into a power grid, comprising: a DC voltage converter circuit configured to receive a DC voltage across first and second input terminals and generate a converted DC voltage across first and second output terminals thereof, the DC voltage converter circuit comprising: a series connected string coupled across the first and second input terminals of the DC voltage converter circuit, the string comprising a first switch coupled between the first input terminal of the DC voltage converter circuit and a first node coupled to a coil tap of a storage choke, and a second switch coupled between the second input terminal of the DC voltage converter circuit and a second node coupled to a first terminal of the storage choke; a first diode coupled between the second node and the first output terminal of the DC voltage converter circuit; and a second diode coupled between a second terminal of the storage choke and the second output terminal of the DC voltage converter circuit; an inverter circuit configured to convert the converted DC voltage received at first and second input terminals thereof from the DC voltage converter circuit to a grid potential at first and second output terminals thereof, the inverter circuit comprising an intermediate circuit comprising first and second series connected capacitors coupled across the first and second input terminals of the inverter circuit, and forming a ground terminal at a connection node therebetween, wherein the first and second output terminals of the DC voltage converter are coupled to the first and second input terminals of the inverter circuit, respectively, and wherein the ground terminal of the inverter circuit is coupled to the DC voltage converter circuit.