An apparatus including a rotating member, a resolver and a mounting structure. The resolver includes a resolver stator and a resolver rotor fixedly mounted on the rotating member via a mounting structure. The mounting structure has a low magnetic relative permeability and isolates the resolver rotor from the rotating member by preventing direct contact between the rotating member and the resolver rotor. The disclosed apparatus may be an electric machine having a rotor fixed to the rotating member and be suitable for use in a hybrid vehicle. The mounting structure advantageously has a relative permeability of no greater than about 2 and may be formed out of stainless steel material. The rotating member may be a rotor hub formed out of steel material having a relative permeability of at least about 50.

In a variable-speed synchronous generator-motor device, a frequency converter is connected to armature winding of the synchronous machine, an armature current of the synchronous machine are converted into a direct-axis and a quadrature-axis based on a rotational phase reference, and the current is controlled. The variable-speed synchronous machine-motor device includes a phase calculator calculates and outputs a target voltage phase of the synchronous machine based on a target frequency reference of the synchronous machine for a quadrature-axis current command value. A phase lead compensating is performed for a result of comparing the voltage phase of the synchronous machine and the target voltage phase and the result is added to the quadrature-axis current command value. A rotational speed is regulated by a synchronizing force with respect to a target frequency. The voltage phase fluctuation on the AC system side is biased to the compared result, and the synchronization force is simulated.

An electrically excited synchronous motor, including a stator, including a stator core and a stator winding. The stator core is provided with a plurality of stator slots uniformly distributed around a rotational axis of the electrically excited synchronous motor, and the stator winding is accommodated in the stator slots. Also provided is a rotor, including a rotor core and a rotor excitation winding. The stator slots are inclined relative to the rotational axis at a predetermined inclination angle. A drive system can include such an electrically excited synchronous motor, and a vehicle can include such a drive system.

Rotor (1) of an electric machine, in particular an electrically excited synchronous machine, comprising a rotor shaft (3) which can be rotated about a rotor axis (2), in particular which is a hollow shaft, comprising multiple separate salient poles (4) arranged around a circumferential direction of the rotor (1), which are anchored in a rotor yoke (5), in particular interlockingly, characterized in that the rotor yoke (5) is formed in the motor shaft (3).

Rotor (1) of an electric machine, in particular an electrically excited synchronous machine, comprising a rotor shaft (3) which can be rotated about a rotor axis (2), in particular which is a hollow shaft, comprising multiple separate salient poles (4) arranged around a circumferential direction of the rotor (1), which are anchored in a rotor yoke (5), in particular interlockingly, characterized in that the rotor yoke (5) is formed in the motor shaft (3).

A rotor for a current-excited synchronous machine, includes a rotor main body which has a plurality of rotor teeth distributed around the circumference and rotor slots formed therebetween, the rotor teeth being wound, along the rotor slots and on the front side, with conductor material in order to form a winding, the conductor material being surrounded by a potting compound, thereby forming a potting body for mechanical stabilization, the potting body having segments on the front sides in extension of the rotor slots, and in at least one of the segments the material cohesion of the potting compound is selectively weakened or eliminated at least in regions or portions.