Abstract: In order to achieve improved single-phase operation of an inverter having a first input pole and a second input pole and including at least three phase branches, each having at least one upper power switch and at least one lower power switch connected in series to the at least one upper power switch via an output pole a switching unit is provided. The switching unit is designed to switch the inverter from multi-phase operation to single-phase operation by closing a center point connection switch in order to connect the third output pole to the DC link center point. The switching unit is further designed, in single-phase operation, to effect a control of the upper and lower power switch of the third phase branch for symmetrizing the DC link voltages at the first and second DC link capacitors.

Abstract: Power supply for an inverter and method for operating power supply. Power supply includes a throttle arranged to connect an output end of the inverter to an electric power supply network; a secondary-side auxiliary winding that is arranged on the throttle to transmit an output voltage (UA) of the inverter to a secondary side of the throttle; and a comparator unit. The comparator unit compares a voltage (U1) of the electric supply network with the voltage (U2) of the secondary side of the throttle, to supply, depending upon a result of the comparison of the electric supply network voltage (U1) to the secondary side voltage (U2) of the throttle, electric power to the power supply either from the electric supply network or via the secondary-side auxiliary winding.

Abstract: To be able to maintain the power supply of an inverter which is supplied with power from a supply network even in the event of a power failure, it is proposed according to the invention that in the event of a power failure, the electric power for the power supply (2) of the inverter (1) is obtained from a throttle (7) of the inverter (1) at the output end via an auxiliary winding (13).