A system including a generator and a controller. The generator includes a permanent magnet generator (PMG), and an exciter. The controller manages operations of the generator. The controller includes an alternating current to direct current (AC-to-DC) converter that generates a direct current (DC) voltage, an exciter drive that provides a DC current to the exciter of the generator using the DC voltage created by the AC-to-DC converter in accordance with the control signal, and a regulator controller that drives the active AC-to-DC converter.

A brushless starter-generator system is contained within a single housing. The housing has a first end with an opening to receive a drive spline from a motive source and an opposing second end. A brushless, rotating machine is located adjacent the first end and is kinetically connectable to the drive spline. A power control unit is adjacent the second end and electrically coupled to the brushless, rotating machine. The brushless, rotating machine is selected from the group consisting of a synchronous machine, a permanent magnet machine, and an induction machine. Electrical and mechanical interfaces are identical to a like-rated brushed version for a true “drop-in” replacement capability to facilitate replacements and up-grades.

A system may include an independent speed variable frequency (ISVF) generator configured to convert torque from a shaft to an AC power signal. The ISVF generator may have one or more pole pairs with an equivalent shaft frequency equaling a shaft frequency multiplied by the number of pole pairs. A generator control unit may set a generator output frequency of the ISVF generator equal to a lower frequency limit of an AC bus when the equivalent shaft frequency is less than the lower frequency limit, set the generator output frequency of the ISVF generator equal to an upper frequency limit of the AC bus when the equivalent shaft frequency is greater than the upper frequency limit, and set the generator output frequency of the ISVF generator equal to the equivalent shaft frequency when the equivalent shaft frequency is between the lower frequency limit and the upper frequency limit.

The disclosed embodiments aim to improve upon existing multi stage generators for providing power to a load. In particular, embodiments of the invention include a regulator situated between the output of a pilot exciter and the main exciter of a multi stage generator system, the regulator arranged to limit the voltage available to a field current control element which sets the field current supplied to the main exciter.

A power generation system for a drilling tool includes a turbine, an alternator, a converter and a first active rectifier control (ARC). The turbine is adapted to be driven by a fluid flow in a well. The alternator is coupled to the turbine and generates an alternative current (AC). The converter converts the AC to direct current (DC) and carries out active rectification. The first active rectifier control (ARC) controls the active rectification of the converter.

A kinetic power generation unit (1,2,3) improves the magnetic field of an electric motor (1a) and the magnetic field of a power generator (1b) into a same magnetic field coupling of a same rotor (10), so that the rotors (10) of electric motor (la) and the power generator (1b) have the same rotational direction, and an exciting winding (12a) of the electric motor (1a) and a field winding (12b) of the power generator (1b) change and transmit phases sequentially to a phase voltage by a DC brushless drive controller (40), so that an interference effect on the counter electromotive force of the electric motor (1a) and the counter-electromotive force of the power generator (1b) is changed to a positive effect.

A system may include an independent speed variable frequency (ISVF) generator configured to convert torque from a shaft to an AC power signal. The ISVF generator may have one or more pole pairs with an equivalent shaft frequency equaling a shaft frequency multiplied by the number of pole pairs. A generator control unit may set a generator output frequency of the ISVF generator equal to a lower frequency limit of an AC bus when the equivalent shaft frequency is less than the lower frequency limit, set the generator output frequency of the ISVF generator equal to an upper frequency limit of the AC bus when the equivalent shaft frequency is greater than the upper frequency limit, and set the generator output frequency of the ISVF generator equal to the equivalent shaft frequency when the equivalent shaft frequency is between the lower frequency limit and the upper frequency limit.

A rotor for a synchronous machine of a motor vehicle includes an excitation coil configured to generate a magnetic field necessary for rotation of the rotor in a stator of the synchronous machine. The rotor also includes a supply circuit, to which energy is fed contactlessly such that the supply circuit supplies the excitation coil with the energy. The rotor also includes a demagnetization circuit configured to demagnetize the excitation coil, which, upon collapse of the energy supply of the excitation coil, diverts a current flowing through the excitation coil into a circuit branch in which at least one component for demagnetization is arranged, wherein the at least one component is also configured to perform a protection function to protect the supply circuit against an induced voltage generated at the excitation coil.

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 dual-wound machine comprises a dual-wound generator supplying power to two separate powered zones. The generator comprises a wound rotor with a field winding and a stator with two sets of phase windings and a field control loop that controls the excitation voltage applied to the field winding and therefore the magnetic field produced by the rotor, in order to maintain a constant field flux in the generator and mitigate dynamic coupling between the two sets of phase windings when supplying power to unbalanced loads.