Abstract: A fault-tolerant synchronisation source for excitation control of a three-phase generator system that combines point of regulation (POR) signals representing parameters comprising voltage and current for each phase at the POR to generate a fault-tolerant synchronisation signal.

Abstract: An improved passive cooling system for an aircraft APU compartment that includes a lightweight annular air-cooled oil cooler that is strategically oriented and shrouded to face its annular inlet away axially downstream from the exhaust of the APU to make it inherently fireproof to flames from the APU or any location within the APU compartment that fuel can accumulate.

Abstract: A ram air turbine (RAT) prevents release of its turbine blades due an over-speed condition by detecting an over-speed condition with a turbine hub-mounted centrifugally operated trigger mechanism and rotating the blades to a fixed coarse pitch position with a release mechanism that responds to the trigger mechanism.

Abstract: A ram air turbine (RAT) prevents release of its turbine blades due an over-speed condition by detecting an over-speed condition with a turbine hub-mounted centrifugally operated trigger mechanism and rotating the blades to a fixed coarse pitch position with a release mechanism that responds to the trigger mechanism.

Abstract: A motor control system for a wound field synchronous dynamoelectric machine used as an electrical starter and a generator for aeronautical engines that uses its integral auxiliary permanent magnet generator as an angular position sensor in its starting mode.

Abstract: An improved inductor for a DC link that has an auxiliary winding for inducing an opposing magnetic field in a magnetically permeable core with an auxiliary DC current that opposes a magnetic field that a primary winding for the inductor induces along a magnetic path in the core with a DC component of current to reduce magnetic saturation of the inductor due to the DC component.

Abstract: A wound field synchronous (WFS) dynamoelectric machine comprises: a rotor assembly; an exciter generator section comprising a stationary multiphase exciter stator winding for receiving excitation power from a multiphase alternating current (AC) source to generate an exciter stator magnetic field, a multiphase exciter rotor winding in the rotor assembly for generating multiphase AC excitation power as it cuts through the exciter stator magnetic field and a rotating rectifier assembly in the rotor assembly for converting the multiphase AC excitation power to direct current (DC) excitation power; a synchronous machine section comprising a DC main rotor winding in the rotor assembly for generating a main rotor magnetic field and a stationary multiphase main stator winding for receiving a multiphase AC control signal to generate a rotating main stator magnetic field that interacts with the main rotor magnetic field to rotate the rotor assembly; and an impedance that selectively connects one phase of the exciter st

Abstract: A method of correcting the determination of extended rotor flux using a lag function and a correction algorithm that closely approximates a pure integrator function to correct for lag function errors that can extend the EFS control down to dynamoelectric machine speeds corresponding to as low as 10 Hz electrical frequency.

Abstract: A Hall-Effect sensor assembly for a rotating electric machine comprises a thin, removable tubular substrate with Hall-Effect sensors and associated connection wiring mounted on it that slips underneath the wound stator end turns of the stator for the rotating electric machine to make the assembly easily removable for installation and repair.

Abstract: A starter/generator system for a gas turbine engine used in aeronautical applications that couples a single dynamoelectric machine to the gas turbine engine through a torque converter in a starting mode, and engages the engine to the dynamoelectric machine through a mechanical differential in a generating mode after the engine reaches self-sustaining speed and combines the output of the engine and the torque converter to regulate the frequency of AC generated by the dynamoelectric machine within a range of frequencies suitable for on-board electrical equipment by dynamically regulating the flow of hydraulic fluid to the torque converter.

Abstract: A lubrication system for an expendable gas turbine engine (20) having a rotatable shaft (26) is provided. Bearings (28) journal the shaft (26) for rotation about an axis. The system includes a vessel (46) for containing lubricating oil, a conduit (58) extending from the vessel (46) to the bearings (28), and a solenoid operated valve (70,76) in the conduit (58) and operable to only either fully open or fully closed. A control circuit (16) is provided for pulsing the solenoid (70) at a controlled rate to alternatingly (a) allow oil flow and (b) halt oil flow to the bearings (28) for a time insufficient to cause oil starvation of the bearings (28).

Abstract: A gas-tight electrical connection comprises a conductive substrate with at least one socket for receiving an associated wire, at least one slot in the conductive substrate that penetrates each socket and at least one SMA force ring that slides over the conductive substrate near each slot to clamp the electrical connection when heated to its austenitic state.

Abstract: A stall recovery system for a ram air turbine (RAT) that supplements the operation of a volume fuse in the hydraulic system of the RAT by sensing a stall condition as the combination of low pressure at less than maximum flow and reducing RAT load torque after the sensed stall so that stall recovery is possible.

Abstract: A combined no-back and torque limiter device that automatically prevents back-drive and over-torque actuator conditions with a combination of two compression-type brakes that are selectively operated with a self-energised ball ramp set and torsional spring mechanism.

Abstract: An auxiliary power unit (APU) inlet muff anti-icing system that uses high pressure, high temperature APU compressor delivery air to melt any accumulation of ice and snow near the bottom of the muff with a tracer line coupled to a perforated gull wing fairing mounted within the inlet muff and that uses the compressor delivery air as the primary stream for an ejector to suck ice and snow melt accumulating near the fairing overboard.

Abstract: A field oriented control system for a brushless wound field synchronous machine that determines positioning of a rotor for the machine from exciter stator electrical potentials and current harmonics.

Abstract: A main engine electric start system for gas turbine propelled aircraft that employs a low-power AC electrical power system to serve as an independent grid to control the functions of induction-type dynamoelectric machines coupled to the main propulsion engines and APU as a starter or generator.

Abstract: A starter/generator electrical system for gas turbine powered aircraft with mixed power architecture to combine advantages of each. The mixed power architecture may be selected from constant frequency (CF), adjustable variable frequency (AVF) and narrow range variable frequency (NRVF) alternating current (AC) systems to suit aircraft requirements for on-board electric components and redundancy, with at least two separate power generation systems provided for each gas turbine engine on the aircraft.

Abstract: An improved motor controller for driving polyphase alternating current dynamoelectric machines from a direct current power source that employs two inverter bridges controlled with a state vector modulation symmetrical state sequence that has a desired “chop” frequency so that each of their outputs produce a fundamental component that is exactly in phase but chop frequency components that are exactly 180 degrees out of phase with each other, with their outputs combined through respective interphase transformers to average the potentials of the chop frequency components.

Abstract: A starter/generator system for a gas turbine engine used in aeronautical applications that couples a single dynamoelectric machine to the gas turbine engine through a torque converter in a starting mode, and then disengages the torque converter and engages the engine to the dynamoelectric machine through an adjustable speed transmission in a generating mode after the engine reaches self-sustaining speed, wherein the speed of the adjustable speed transmission is set to match the frequency of AC generated by the dynamoelectric machine with on-board electrical equipment requirements to suit flight conditions.