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.

An aircraft starting and generating system includes a starter/generator that includes a main machine, an exciter, and a permanent magnet generator. The system also includes an inverter/converter/controller that is connected to the starter/generator and that generates AC power to drive the starter/generator in a start mode for starting a prime mover of the aircraft, and that converts AC power, obtained from the starter/generator after the prime mover have been started, to DC power in a generate mode of the. A load-leveling unit (LLU) is selectively coupled with a DC power output from the starter/generator and has an inverter/converter/controller (ICC) with an LLU metal oxide semiconductor field effect transistor (MOSFET)-based bridge configuration that supplies DC power to the DC power output in a supply mode, and that receives DC power from the DC power output, in a receive mode. A LLU bridge gate driver is configured to drive the LLU MOSFET-based bridge during a supply mode and a receive mode using bi-polar pulse width modulation (PWM).

An aircraft starting and generating system includes a starter/generator that includes a main machine, an exciter, and a permanent magnet generator. The system also includes an inverter/converter/controller that is connected to the starter/generator and that generates AC power to drive the starter/generator in a start mode for starting a prime mover of the aircraft, and that converts AC power, obtained from the starter/generator after the prime mover have been started, to DC power in a generate mode of the. A load-leveling unit (LLU) is selectively coupled with a DC power output from the starter/generator and has an inverter/converter/controller (ICC) with an LLU metal oxide semiconductor field effect transistor (MOSFET)-based bridge configuration that supplies DC power to the DC power output in a supply mode, and that receives DC power from the DC power output, in a receive mode. A LLU bridge gate driver is configured to drive the LLU MOSFET-based bridge during a supply mode and a receive mode using bi-polar pulse width modulation (PWM).

In one embodiment, a generator includes a rotor configured to rotate in cooperation with a stator to generate electrical power. An exciter of the generator includes at least one circuit board, a stationary exciter stator, and a control circuit. The circuit board is mechanically coupled to a rotor of the generator and includes at least one coil of an electrical conductor. The stationary exciter stator is configured to induce a current in the at least one coil of the at least one circuit board. The control circuit is configured to modify the current from the at least one coil and provide the modified current to a field of the generator.

A method of assembling a rotating rectifier having multiple radially spaced bus bars with a corresponding fastener to an electrical machine having at least one machine with a stator and a rotor mounted on a rotating shaft, the method includes inserting the rotating rectifier into a hollow portion of the rotating shaft, axially aligning the fasteners with a corresponding radial opening in the rotating shaft, inhibiting an inward radial movement of the fasteners by inserting an inhibiting tool into an interior defined by the multiple radially spaced bus bars, and at least partially securing the fasteners to a corresponding fastener on at least one of the rotor and rotating shaft while the inhibiting tool resides in the interior.

A method of assembling a rotating rectifier having multiple radially spaced bus bars with a corresponding fastener to an electrical machine having at least one machine with a stator and a rotor mounted on a rotating shaft, the method includes inserting the rotating rectifier into a hollow portion of the rotating shaft, axially aligning the fasteners with a corresponding radial opening in the rotating shaft, inhibiting an inward radial movement of the fasteners by inserting an inhibiting tool into an interior defined by the multiple radially spaced bus bars, and at least partially securing the fasteners to a corresponding fastener on at least one of the rotor and rotating shaft while the inhibiting tool resides in the interior.

A power electronic arrangement for an externally excited synchronous machine is disclosed and may comprise a heat sink, at least one inverter power module including an inverter and at least one exciter power module including an exciter circuit. The at least one inverter power module may be mounted in a predefined relative inverter position and orientation on the heat sink by material bonding The heat sink and the exciter power module may each include positioning devices configured to interlock such that a desired relative exciter power module position and orientation relative to the inverter power modules is produced by interlocking the positioning devices of the heat sink and the exciter power module.

A power electronic arrangement for an externally excited synchronous machine is disclosed and may comprise a heat sink, at least one inverter power module including an inverter and at least one exciter power module including an exciter circuit. The at least one inverter power module may be mounted in a predefined relative inverter position and orientation on the heat sink by material bonding The heat sink and the exciter power module may each include positioning devices configured to interlock such that a desired relative exciter power module position and orientation relative to the inverter power modules is produced by interlocking the positioning devices of the heat sink and the exciter power module.