A field winding type rotary machine includes a stator having a stator core and a stator coil wound on the stator core, a rotor having a rotor core and a rotor field coil wound on the rotor core, and a rectifier element connected between both ends of the rotor field coil. The field winding type rotary machine includes a capacitor having a first terminal connected to an anode terminal of the rectifier element and a second terminal connected to any point of the rotor field coil.

Unique systems, methods, techniques and apparatuses of an exciterless synchronous generator are disclosed. One exemplary embodiment is an exciterless synchronous generator comprising a stator, a rotor, and a startup excitation system. The stator includes a set of stator windings. The rotor includes an energy harvest winding, a DC power supply including a DC bus and coupled to the energy harvest winding, and a field winding coupled to the DC power supply. The startup excitation system comprises one of a magnetic field generation system structured to generate a magnetic field received by the energy harvest winding in response to a rotation of the rotor, wherein the magnetic field is converted to DC power with the DC power supply and transmitted to the field winding; or a rotor DC power source including and diode coupled in series across the DC bus.

An electric machine (21) having a stator (20) and having a rotor (29) rotatably mounted to the stator (20) is specified. The stator (20) comprises a stator winding (24), at least three teeth (23), and at least three grooves (22). In each case, one tooth (23) of the stator (20) is arranged between two grooves (22) along a circumference of the stator (20), and the stator winding (24) has at least three coils (25), wherein each of the coils (25) is wound around a tooth (23) of the stator (20), so that the stator winding (24) is a concentrated winding. In addition, the winding direction of all coils (25) is the same, each of the coils (25) is designed to be fed with its own phase current, and the stator (20) is designed to generate at least two rotary fields having different numbers of pole pairs independently of each other, in particular simultaneously. In addition, an activation unit (40) for the electric machine (21) and a method for operating an electric machine (21) are specified.

A synchronous machine (100) has a frame (110), a shaft (115), a main section (120), and an exciter section (125). The main section (120) has a stator winding (130) which is mounted on the frame, and a rotor winding (135) which is mounted on the shaft. The exciter section has a transformer (140) and a rectifier (145). The transformer has a primary winding (140A) mounted on the frame and a secondary winding (140B) mounted on the shaft. The rectifier is mounted on the shaft and rectifies an output of the secondary winding to provide a rectified output to the rotor. A control unit (170) provides a high-frequency control signal to the primary winding. This signal is magnetically coupled to the secondary winding, rectified, and then applied to the rotor to control the operation of the synchronous machine.

An alternator includes an exciter field device generating an exciter magnetic field in a first air gap, an exciter armature device configured to rotate with respect to the exciter magnetic field and impart a first voltage in a first set of coils at the first air gap, a main stator device including a second set of coils, and a rotor field device configured to be energized by the first current in the first set of coils and generate a main magnetic field that imparts a second voltage on the main stator device at a second air gap. The main stator device and the exciter field device lie in on a common plane normal to an axis of rotation, and the exciter armature device is inwardly spaced from the exciter field device, main stator device, and the rotor field device.

An alternator includes an exciter field device generating an exciter magnetic field in a first air gap, an exciter armature device configured to rotate with respect to the exciter magnetic field and impart a first voltage in a first set of coils at the first air gap, a main stator device including a second set of coils, and a rotor field device configured to be energized by the first current in the first set of coils and generate a main magnetic field that imparts a second voltage on the main stator device at a second air gap. The main stator device and the exciter field device lie in on a common plane normal to an axis of rotation, and the exciter armature device is inwardly spaced from the exciter field device, main stator device, and the rotor field device.

Unique systems, methods, techniques and apparatuses of an exciterless synchronous machine are disclosed. One exemplary embodiment is a salient pole rotor for an electric machine comprising one set of pole pairs including a first, second, and third pole pair; a field winding; a set of energy harvest windings, each winding mounted to each of the plurality of pole pairs and structured to receive a harmonic component of AC power from a stator; and a DC power supply structured to receive the harmonic component from the set of energy harvest windings, convert the harmonic component to DC power, and output the DC power to the field winding. The set of energy harvest windings are arranged in a first sequence on the first pole pair, a second sequence on the second pole pair, and a third sequence on the third pole pair, and each sequence is different.

A synchronous machine (100) has a frame (110), a shaft (115), a main section (120), and an exciter section (125). The main section (120) has a stator winding (130) which is mounted on the frame, and a rotor winding (135) which is mounted on the shaft. The exciter section has a transformer (140) and a rectifier (145). The transformer has a primary winding (140A) mounted on the frame and a secondary winding (140B) mounted on the shaft. The rectifier is mounted on the shaft and rectifies an output of the secondary winding to provide a rectified output to the rotor. A control unit (170) provides a high-frequency control signal to the primary winding. This signal is magnetically coupled to the secondary winding, rectified, and then applied to the rotor to control the operation of the synchronous machine.

A synchronous machine (100) has a frame (110), a shaft (115), a main section (120), and an exciter section (125). The main section (120) has a stator winding (130) which is mounted on the frame, and a rotor winding (135) which is mounted on the shaft. The exciter section has a transformer (140) and a rectifier (145). The transformer has a primary winding (140A) mounted on the frame and a secondary winding (140B) mounted on the shaft. The rectifier is mounted on the shaft and rectifies an output of the secondary winding to provide a rectified output to the rotor. A control unit (170) provides a high-frequency control signal to the primary winding. This signal is magnetically coupled to the secondary winding, rectified, and then applied to the rotor to control the operation of the synchronous machine.

The present disclosure broadly relates to apparatuses and methods for generating electric power. More particularly, the present disclosure relates to a self-excited electric generator. The self-excited electric generator may include auxiliary windings to provide a source of electricity to an associated generator control unit (GCU). The apparatuses and methods of the present invention may provide added benefits of reducing excitation requirements from the GCU. Thereby, the apparatuses and methods may reduce cost, weight, and size of an electric generator, and may increase reliability of associated systems.