Drive unit comprising: • a power converter, which is connectable to a working machine, comprising an intermediate circuit, which is coupleable firstly to a first inverter and secondly to a second inverter, wherein the first inverter is designed to be connectable to a motor on the AC voltage side and is connected to the intermediate circuit on the DC voltage side, and wherein the second inverter is connected to the intermediate circuit on the DC voltage side and is connectable to the working machine on the AC voltage side, and wherein the second inverter is designed to drive the working machine in such a way that the working machine is operable either as a motor or as a generator; • a link to at least one energy store; • a switching unit (8, 13) connected to the power converter, wherein the switching unit (8, 13) is operable in a first operating mode or second operating mode, wherein in the first operating mode the switching unit (8, 13) is designed to couple the power converter to the at least one energy store in order to enable an energy flow from the at least one energy store via the switching unit (8, 13) to the intermediate circuit of the power converter and wherein in the second operating mode the switching unit (8, 13) is designed to disconnect the power converter from the at least one energy store; wherein the drive unit comprises an energy store charging unit, which is connectable to the power converter in order to make energy available to the energy store, wherein the charging of the energy store is effected via the energy store charging unit, if the switching unit (8, 13) is in the second operating mode, and wherein the switching unit (8, 13) is designed to couple the power converter to a supply network terminal in order to enable an energy flow from the intermediate circuit of the power converter via the switching unit (8, 13) toward the supply network terminal. • a power converter, which is connectable to a working machine, comprising an intermediate circuit, which is coupleable firstly to a first inverter and secondly to a second inverter, wherein the first inverter is designed to be connectable to a motor on the AC voltage side and is connected to the intermediate circuit on the DC voltage side, and wherein the second inverter is connected to the intermediate circuit on the DC voltage side and is connectable to the working machine on the AC voltage side, and wherein the second inverter is designed to drive the working machine in such a way that the working machine is operable either as a motor or as a generator; • a link to at least one energy store; • a switching unit (8, 13) connected to the power converter, wherein the switching unit (8, 13) is operable in a first operating mode or second operating mode, wherein in the first operating mode the switching unit (8, 13) is designed to couple the power converter to the at least one energy store in order to enable an energy flow from the at least one energy store via the switching unit (8, 13) to the intermediate circuit of the power converter and wherein in the second operating mode the switching unit (8, 13) is designed to disconnect the power converter from the at least one energy store;