Abstract: A method for determining phase currents for current control of an electric machine of a drive system for a motor vehicle is provided. Measured characteristics of the phase currents that are supplied to at least three phases of a set of phases of the electric machine and that are measured by at least three phase current sensors of a set of phase current sensors of the drive system are received. Zero crossings in the at least three measured phase current sensor-specific characteristics are identified, a phase current value of at least one other characteristic is determined, per characteristic, for at least one zero crossing. The phase current values are used for determining a characterization value, describing a gain factor of each phase current sensor, for the respective phase current sensor, and the phase currents for the current control are determined based on the characterization values of the phase current sensors.

Abstract: A method for controlling a multiphase voltage signal in a closed-loop manner is provided. The multiphase voltage signal is supplied to at least one phase set of a stator of an electric machine of a drive system of a motor vehicle for the purpose of generating a torque-specific, rotary magnetic field. The method includes determining a fundamental space vector representing a fundamental of the voltage signal, determining at least one harmonic space vector representing a harmonic of the voltage signal, adding the fundamental space vector and the at least one harmonic space vector to form a summed space vector, determining whether the summed space vector exceeds a predetermined threshold value, and limiting the summed space vector in such a manner that the limited summed space vector falls short of the threshold value.

Abstract: A rotor for a separately excited inner rotor synchronous machine of an electrically drivable motor vehicle, having a plurality of rotor windings for forming a rotor magnetic field and a rotor core for holding the rotor windings, wherein the rotor core has an annular rotor yoke with a number of rotor poles corresponding to a number of rotor windings. The poles are arranged along a rotor circumference on the rotor yoke and the rotor windings are arranged on the poles, wherein the rotor poles are formed of multiple parts and each has a rotor tooth and at least one pole shoe element separate therefrom. The rotor teeth are formed as a single piece with the rotor yoke, and the pole shoe elements are mechanically connectable to the rotor teeth after arranging the rotor windings on the rotor teeth. Also provided are the synchronous machine, a motor vehicle and a method.

Abstract: A measuring device for measuring the wear of carbon brushes includes: a slip ring; a carbon brush, which is arranged for sliding in a sliding direction and which is preloaded into sliding contact with the slip ring; and an indicator material, which extends in the sliding direction in, on or next to the carbon brush and is connected to the carbon brush in such a way that the indicator material moves together with the carbon brush at least with respect to the sliding direction. The indicator material is preloaded into sliding contact with the slip ring. An insulator is arranged between the carbon brush and the indicator material and electrically insulates the carbon brush from the indicator material. A resistance-measuring apparatus measures the resistance between two measurement points, between which at least a section of the indicator material and a section of the slip ring lie, wherein the specific resistance of the indicator material is greater than the specific resistance of the carbon brush.