Abstract: A system and method are disclosed for advantageously using field-controlled high-frequency alternators for the generation of controlled high-voltage DC power from variable speed mechanical power sources such as wind turbines, water wheels, and gas or steam turbines. The production of controlled high-voltage DC power without involving hard switching of the full output power is described.

Abstract: A method is disclosed for arranging and exciting the stator, rotor and various windings of a multi-stage brushless high frequency alternator so that the resulting multiple high frequency sub-phase armature winding outputs can be rectified and commutated into desired phases of power-frequency alternating current (AC) electrical output, including single-phase, split-phase, three-phase and other multiple phase output. Power frequency currents in field windings control output amplitude, output frequency, and output phase. If desired, DC power output can be accommodated as zero power-frequency operation. Devices incorporating this arrangement are suitable of generating fixed frequency electrical power while accommodating variable speed rotation of a generator shaft and offer multiple advantages over existing techniques. The capability to generate speed independent electric power allows natural power sources such as windmills and hydro-power stations to be efficiently coupled to fixed frequency power grids.

Abstract: A method is disclosed for arranging and exciting the stator, rotor and various windings of a multi-stage brushless high frequency alternator so that the resulting multiple high frequency sub-phase armature winding outputs can be rectified and commutated into desired phases of power-frequency alternating current (AC) electrical output, including single-phase, split-phase, three-phase and other multiple phase output. Power frequency currents in field windings control output amplitude, output frequency, and output phase. If desired, DC power output can be accommodated as zero power-frequency operation. Devices incorporating this arrangement are suitable of generating fixed frequency electrical power while accommodating variable speed rotation of a generator shaft and offer multiple advantages over existing techniques. The capability to generate speed independent electric power allows natural power sources such as windmills and hydro-power stations to be efficiently coupled to fixed frequency power grids.

Abstract: A method is disclosed for arranging and exciting the stator, rotor and various windings of a multi-stage brushless high frequency alternator so that the resulting multiple high frequency sub-phase armature winding outputs can be rectified and commutated into three phase power frequency alternating current (AC) electrical output. Power frequency currents in field windings control output amplitude, output frequency, and output phase. Devices incorporating this arrangement are suitable of generating fixed frequency electrical power while accommodating variable speed rotation of a generator shaft and offer multiple advantages over existing techniques. The capability to generate speed independent electric power allows natural power sources such as windmills and hydro-power stations to be efficiently coupled to fixed frequency power grids.

Abstract: A method is disclosed for arranging and exciting the stator, rotor and various windings of a multi-stage brushless high frequency alternator so that the resulting multiple high frequency sub-phase armature winding outputs can be rectified and commutated into three phase power frequency alternating current (AC) electrical output. Power frequency currents in field windings control output amplitude, output frequency, and output phase. Devices incorporating this arrangement are suitable of generating fixed frequency electrical power while accommodating variable speed rotation of a generator shaft and offer multiple advantages over existing techniques. The capability to generate speed independent electric power allows natural power sources such as windmills and hydro-power stations to be efficiently coupled to fixed frequency power grids.

Abstract: A single-pole type generator with low loss magnetic core is excited by a field coil that is part of a low loss series resonant circuit tuned to a desired AC power frequency, which may be frequencies such as 50 Hz or 60 Hz or 400 Hz. The series resonant circuit is excited at the resonant frequency. The resulting resonant behavior of the excitation circuit automatically provides the high driving voltages and sinusoidal energy storage patterns needed to efficiently modulate the magnetic field at the desired power frequency. This modulation of the excitation field is amplified by mechanical power from a rotating shaft and modulates the output current and voltage of a single phase output circuit of the single-pole type generator at that power frequency in a sinusoidal pattern thus delivering alternating current power without any requirement for further electronic rectification, commutation or processing.

Abstract: An arrangement is disclosed to automatically match the resonant frequency of a series resonant circuit to an imposed operating frequency. A series resonant circuit is used to store or modulate magnetic energy or to generate high voltages. The circuit includes a capacitive element in series with an inductive element and voltage driving source. The capacitive element includes a base capacitance in parallel with a switch circuit that is in series with a trim capacitance. The switch circuit regulates the timing and direction of current through the trim capacitance. The capacitance of the capacitive element may be tightly controlled so that the resonant frequency may be closely regulated. A controller regulates the operation of the switch circuit and the voltage driving source as a function of sensed current through the resonant circuit and the driving frequency and amplitude to be matched.

Abstract: An arrangement is disclosed to automatically match the resonant frequency of a series resonant circuit to an imposed operating frequency. A series resonant circuit is used to store or modulate magnetic energy or to generate high voltages. The circuit includes a capacitive element in series with an inductive element and voltage driving source. The capacitive element includes a base capacitance in parallel with a switch circuit that is in series with a trim capacitance. The switch circuit regulates the timing and direction of current through the trim capacitance. The capacitance of the capacitive element may be tightly controlled so that the resonant frequency may be closely regulated. A controller regulates the operation of the switch circuit and the voltage driving source as a function of sensed current through the resonant circuit and the driving frequency and amplitude to be matched.

Abstract: A low inductance electrical machine that may be used as an alternator or motor with low armature inductance is disclosed. Arrangements of complementary armature windings are presented in which the fluxes induced by currents in the armature windings effectively cancel leading to low magnetic energy storage within the machine. This leads to low net flux levels, low core losses, low inductance and reduced tendency toward magnetic saturation. The inclusion of additional gaps in the magnetic circuit allows for independent adjustment of air gap geometry and armature inductance. Separately excited field arrangements are disclosed that allow rotor motion to effect brush-less alternator or brush-less motor operation. An exemplary geometry includes a stator including two annular rings and a concentric field coil together with a rotor structure separated from the stator by four air gaps.

Abstract: A low inductance electrical machine which may be used as an alternator or motor with low armature inductance is disclosed. Arrangements of complementary armature windings are presented in which the fluxes induced by currents in the armature windings effectively cancel leading to low magnetic energy storage within the machine. This leads to low net flux levels, low core losses, low inductance and reduced tendency toward magnetic saturation. Separately excited field arrangements are disclosed that allow rotor motion to effect brushless alternator or brushless motor operation. An exemplary geometry includes a stator including two toroidal rings and a concentric field coil together with a rotor structure separated from the stator by four air gaps. An alternate embodiment allows for counter-rotation of two rotor elements for use as a flywheel energy storage system in which the external gyroscopic effects cancel.