Electrical circuit for generating a three-phase alternating current

Claim 1

An electrical circuit for connecting a three-phase generator to a three-phase power grid, wherein the generator has a star-like circuit layout with a center point and is driven at a variable rpm-rate; said electrical circuit having a forward mode where energy flows from the generator either to the power grid or to an energy-storage device and a reverse mode where energy flows either from the power grid or from the energy-storage device to the generator, said electrical circuit comprising a) to support the forward mode: a generator-adjacent circuit stage with generator-adjacent diode rectifiers and generator-adjacent booster circuits, an intermediate circuit stage with two capacitor groups arranged in series and with a midpoint between the capacitor groups, and a grid-adjacent circuit stage with a grid-adjacent inverter; b) to support the reverse mode: grid-adjacent diode rectifiers and grid-adjacent booster circuits in the grid-adjacent circuit stage, the two capacitor groups in the intermediate circuit stage, and a generator-adjacent inverter in the generator-adjacent circuit stage; wherein the generator-adjacent and grid-adjacent diode rectifiers, booster circuits and inverters together comprise three generator-adjacent inductive elements, three grid-adjacent inductive elements, six generator-adjacent transistors and six generator-adjacent rectifier diodes, six grid-adjacent transistors and six grid-adjacent rectifier diodes; and wherein the electrical circuit further comprises a neutral conductor connected to said center point and said midpoint.