Abstract: The present invention relates to an electrical drive system for or in a motor-vehicle, having at least one multi-phase electric machine, which has a double rotor, wherein the double rotor is made from flux-guiding material made of solid material, with a three-stage or multi-stage inverter circuit for driving the electric machine, which has: a controllable three-stage or multi-stage inverter coupled to the electric machine on the output side, which is designed to supply the electric machine with an AC voltage, and an operating mode setting device, which is designed to operate the inverter as a function of at least one parameter influencing the overall efficiency of the electrical drive system, selectively in a three-stage or multi-stage operation or in a two-stage operation.

Abstract: The present invention relates to a stator for a radial flux double-rotor machine, in particular for a wheel hub motor. The stator includes a stator core; a winding which is placed in the stator core and is designed to be self-supporting for torque support of the stator, wherein the winding protrudes beyond the stator core at least one axial end; and a support device which is arranged axially offset with respect to the stator core and is designed for form-fitting engagement with the winding at the at least one axial end for torque support.

Abstract: A three-level or multi-level inverter circuit for activation of a multiphase electric machine for an electric drive system, with two supply connections couplable to first and second supply potential of voltage supplies, a load output comprising a load output connection for each phase of the electric machine, a controllable three-level or multi-level inverter between the supply connections and the load output designed to convert a direct voltage received on the supply side into an alternating voltage for driving an electric machine, with an operating mode setting device designed to change the inverter between three-level or multi-level operation and two-level operation in dependence upon overall efficiency of the electric drive system, wherein the overall efficiency is a function of the detected phase current of the electric machine and at least one further parameter and/or property of the electric machine which influence the overall efficiency.

Abstract: The present invention relates to an electric drive system for or in a motor vehicle, having: at least one synchronous machine, which has a double rotor and a distributed winding placed in a stator core, wherein the double rotor is constructed from flux-carrying material made of solid material, wherein the winding is designed to be self-supporting for torque support; and at least one three-stage or multi-stage inverter circuit that is coupled to the synchronous machine at a load output and that is designed to convert a DC voltage received on the supply side into an AC voltage via which the synchronous machine can be driven via the load output, wherein the inverter circuit has a controllable three-stage or multi-stage inverter.

Abstract: The present invention relates to controlling an electric drive system. According to the invention, the rotor temperature of an electrical machine is monitored and modulation methods and the switching frequency for controlling the drive system are adapted depending on the rotor temperature.

Abstract: The invention relates to a method and device for operating an electric machine (10) for outputting a predefined torque and a predefined rotational speed, comprising the following steps: providing (420) a first and a second operating mode for the operation of the electric machine (10); detecting (430) a temperature of the electric machine (10); and operating the electric machine (10) in the first operating mode (440) if the detected temperature falls below a threshold value, and operating the electric machine (10) in the second operating mode (450) if the detected temperature corresponds with the threshold value or exceeds same.

Abstract: The invention relates to a method and device for operating an electric machine (10) for outputting a predefined torque and a predefined rotational speed, comprising the following steps: providing (420) a first and a second operating mode for the operation of the electric machine (10); detecting (430) a temperature of the electric machine (10); and operating the electric machine (10) in the first operating mode (440) if the detected temperature falls below a threshold value, and operating the electric machine (10) in the second operating mode (450) if the detected temperature corresponds with the threshold value or exceeds same.