Abstract: A system can include a first generator configured to operate in a first speed range to produce a predetermined output characteristic, a second generator configured to operate at a second speed range different from the first speed range to produce the predetermined output characteristic, and a controller configured to activate the first generator at and/or above a first low activation speed and at and/or below a first high activation speed within the first speed range. The controller can be configured to activate the second generator at and/or above a second low activation speed within the second speed range. The controller can be configured to deactivate the first generator at and/or above a first high deactivation speed. The controller can be configured to deactivate the second generator at and/or below a second low deactivation speed.

Abstract: An electric motor control system including an electric motor having a winding with a first and second end, a motor controller having a phase lead, the motor controller operable to direct a phase current to the phase lead. The electric motor control system also includes a first switching device that provides an electrical connection between the phase lead and the first end of the first winding when in a disabled state, and thereby flowing the phase current from the phase lead to the first end of the first winding, and a second switching device operably connected to the motor controller and providing an electrical connection between the second end of the first winding and a common point, when in an enabled state. The motor controller is operable to change the state of the first switching device to enabled, and the second switching device to disabled, under selected conditions.

Abstract: An electric motor control system, including an electric motor having a first winding set including first and second parallel windings, the first and second windings operable to each current based on the combined phase current, and a differential current sensor operably coupled to the first winding and the second winding. The differential current sensor measuring a differential current flowing through the first winding and the second winding and operable to transmit a signal indicative of the differential current based on the measuring. The system also includes a motor controller connected to the electric motor, the motor controller operable to direct the combined phase current through the phase lead, receive the differential current signal, determine if the differential current flowing through the winding set exceeds a selected threshold, and identify a health status of the motor winding set as degraded if the differential current exceeds the selected threshold.

Abstract: Disclosed is a system for a gas turbine engine, the gas turbine engine comprising a primary shaft, the system including a rotor shaft; a plurality of components connected to the rotor shaft, including a wound field synchronous main machine (MM) and a permanent magnet generator (PMG); and wherein the PMG, alone or with the MM provide torque to change rotational speed of the rotor shaft, thereby changing rotational speed of the primary shaft.

Abstract: A lamination for an electrical machine lamination stack includes a body defining a plurality of winding slots on an inner diameter thereof and at least one inner diameter cleat aperture defined by the body configured to receive a cleat in an unlocked position and to interfere with the cleat when the cleat is transitioned to a locked position within the inner diameter cleat aperture such that a plurality of laminations can be stacked and locked together by the cleat.

Abstract: A multi-rotor electric machine includes a first rotor, a stator, and a second rotor. The stator is disposed concentric with the first rotor and is disposed radially outward from the first rotor. The stator has a first plurality estate or windings disposed proximate first stator teeth of the stator. The stator has a second plurality of stator windings disposed proximate second stator teeth of the stator. The second rotor is disposed concentric with and is disposed radially outward from the stator. The second rotor is rotatable relative to the first rotor.

Abstract: A method of cooling a shaft of a gas turbine engine includes moving a control valve towards a position that inhibits fluid flow from a high pressure air source to an air turbine starter and enables fluid flow from a blower motor to the air turbine starter, in response to a gas turbine engine shutdown. The method further includes operating the blower motor to provide air to the air turbine starter.

Abstract: A rotor for an electrical machine includes a rotor core having a plurality of circumferentially spaced apart rotor poles. Windings are seated in gaps between circumferentially adjacent pairs of the rotor poles. A wedge secures the windings in each gap. The wedge includes a first member made of a first material and at least one second member made of a second material. The second material has a higher electrical conductivity than the first material. The wedge is configured to supply Q-axis damping. A pair of end plates is connected electrically to the at least one second member at opposing longitudinal ends thereof thereby completing a Q-axis winding circuit for each wedge.

Abstract: A generator arrangement includes a stator with armature winding, a rotor with one or more permanent magnets supported for rotation relative to the stator, a variable speed drive, and a control module. The variable speed drive is connected to the rotor for rotating the rotor within a predetermined speed range. The control module is disposed in communication with the armature windings and is operatively connected to the variable speed drive to maintain constant output voltage as load changes by varying rotational speed of the rotor.

Abstract: A rotor for an electrical machine includes a rotor core having a plurality of circumferentially spaced apart rotor poles. A plurality of windings are seated in gaps between circumferentially adjacent pairs of the rotor poles. A respective wedge secures the windings in each gap configured to supply Q-axis damping. A pair of end plates are connected electrically to the wedges at opposing longitudinal ends thereof thereby completing a Q-axis winding circuit for each wedge.

Abstract: An aircraft main power generation system includes a rotor shaft, a main power generator a permanent magnet, an exciter, an aircraft power bus, and a generator control unit. The generator control unit is configured to provide a control current to the exciter in response to a speed of the main power generator reaching a threshold speed and electrically couple the main power generator to the aircraft power bus in response to the speed of the main power generator reaching a minimum operating speed, the threshold speed being lower than the minimum operating speed; or provide a control current to the exciter in response to the speed of the main power generator reaching a predetermined speed and electrically coupling the main power generator to the aircraft power bus in response to a time period elapsing after the speed of the main power generator has reached the predetermined speed.

Abstract: An aircraft main power generation system includes a rotor shaft, a main power generator a permanent magnet, an exciter, an aircraft power bus, and a generator control unit. The generator control unit is configured to provide a control current to the exciter in response to a speed of the main power generator reaching a threshold speed and electrically couple the main power generator to the aircraft power bus in response to the speed of the main power generator reaching a minimum operating speed, the threshold speed being lower than the minimum operating speed; or provide a control current to the exciter in response to the speed of the main power generator reaching a predetermined speed and electrically coupling the main power generator to the aircraft power bus in response to a time period elapsing after the speed of the main power generator has reached the predetermined speed.

Abstract: A multiphase switched flux electric machine including a rotary drive shaft, a ferromagnetic salient pole rotor assembly operably coupled to the rotary drive shaft having a plurality of rotor teeth defining a circumferential outer periphery of the rotor assembly, and a stator assembly. The stator assembly includes a ferromagnetic stator core, a plurality of permanent magnets positioned substantially equidistant about an inner circumference of the stator core, a plurality ferromagnetic stator teeth mounted to the permanent magnets on the stator core with distal ends forming an inner periphery of the stator assembly, the inner periphery proximate the outer axial periphery of the rotor assembly separated by an air gap; and a plurality of stator coils with an axial active portions disposed within selected teeth of the plurality of ferromagnetic stator teeth.

Abstract: An electric machine includes a phase lead and a winding set with first and second windings. The first and second windings are connected to the phase lead and are connected electrically in parallel with one another. A current sensor is coupled to the first winding and is arranged to measure a portion of current flowing through the phase lead which flows through the first winding.

Abstract: A permanent magnet machine includes a rotor including a rotor hub and a plurality of permanent magnets embedded in the rotor in a circumferential pattern. The rotor includes a respective bridge between each circumferentially adjacent pair of the permanent magnets. Each bridge is of a different material than that of the rotor hub, and the rotor hub and bridges are integral with one another.

Abstract: A system has an electric motor having a stator and a rotor. The rotor rotates with a shaft and the shaft drives a fluid rotor. A control senses a fault condition on the electric motor. The control actuates a speed reduction feature when a fault is detected to bring rotation of the motor rotor and the fluid rotor to a stop more rapidly than if the speed reduction feature had not been actuated.

Abstract: An electrical machine includes a with a parallel first and second phase windings. A first neutral bus is connected to the first phase winding and a second neutral bus is connected to the second phase winding. A first voltage sensor is coupled to the first neutral bus and a second voltage sensor coupled to the second phase winding for monitoring current imbalance between the first and second phase windings.

Abstract: A rotor for an electrical machine includes a rotor core having a plurality of circumferentially spaced apart rotor poles. Windings are seated in gaps between circumferentially adjacent pairs of the rotor poles. A wedge secures the windings in each gap. The wedge includes a first member made of a first material and at least one second member made of a second material. The second material has a higher electrical conductivity than the first material. The wedge is configured to supply Q-axis damping. A pair of end plates is connected electrically to the at least one second member at opposing longitudinal ends thereof thereby completing a Q-axis winding circuit for each wedge.

Abstract: A generator arrangement includes a stator with armature winding, a rotor with one or more permanent magnets supported for rotation relative to the stator, a variable speed drive, and a control module. The variable speed drive is connected to the rotor for rotating the rotor within a predetermined speed range. The control module is disposed in communication with the armature windings and is operatively connected to the variable speed drive to maintain constant output voltage as load changes by varying rotational speed of the rotor.

Abstract: An electric machine includes a phase lead and a winding set with first and second windings. The first and second windings are connected to the phase lead and are connected electrically in parallel with one another. A current sensor is coupled to the first winding and is arranged to measure a portion of current flowing through the phase lead which flows through the first winding.