Abstract: An electric power starter/generator system for converting electrical energy from a remote dc electrical power source coupled to a dc distribution bus to mechanical energy to start a turbine engine in a start mode, and for converting mechanical energy from the turbine engine to electrical energy to power utilization equipment connected to the dc bus in a generate mode, comprises a switched reluctance machine, an inverter having a dc input/output coupled to the dc distribution bus, and at least a first and a second switch coupling each of the machine's phase windings to the dc bus, and at least a first and a second diode for cross-cupling each of said phase windings to the dc bus, and a controller coupled to the inverter for monitoring and controlling system performance during the start mode and the generate mode of system operation.

Abstract: A motor generator system in accordance with the invention includes a prime mover (21) for driving an output shaft (18); a main motor generator (16, 105), having a rotor driven by the output shaft, for producing electrical power on a plurality of stator phase windings (36a-36c) in response to the prime mover rotating the output shaft and for driving the output shaft in response to operation as a motor, an exciter (14, 102), having a rotor driven by the output shaft, for applying excitation to a field winding (34) of the main motor generator during operation for producing electrical power on the plurality of phase windings and for applying current to the field winding of the main motor generator to produce a magnetic field in the field winding during operation of the main motor generator as a motor, a time varying signal source (200) for applying a time varying signal having a fundamental frequency 202 to a field winding (28) of the exciter, a main inverter (114), responsive to signal (302) representing a rotar

Abstract: A control for operating an inverter coupled to a switched reluctance machine includes a relative angle estimation circuit for estimating rotor angle for a phase in the switched reluctance machine. The relative angle estimation circuit estimates a phase voltage and thereby calculates phase flux linkage to estimate the rotor angle.

Abstract: A method of commutation of a switched reluctance machine to allow operation in a generate mode comprises the steps of closing upper and lower switches coupling a stator winding to a power bus during an increase in the inductance of a stator winding to allow a flow of current from the power bus through the winding, opening one of the upper and lower switches when the current reaches a first predetermined value, opening the closed of the upper and lower switches during a decrease in the inductance of a stator winding, and closing one of the upper and lower switches during a period of non-alignment of the rotor and stator pole. The method further includes the step of closing both the upper and lower switches if the monitored current falls below a second predetermined value. In this way, the current through the stator winding is not allowed to decay to zero.

Abstract: A rotating flood cooled machine having reduced windage losses comprises a stator having an inner periphery and a rotor rotatably positioned within the stator separated from the stator by a gap which is filled with fluid. A film divider is rotatably positioned within this gap and is allowed to rotate freely. In such a machine, when the rotor rotates at a speed .omega., the film divider is caused to rotate at a speed of approximately .omega./2. At this speed, the film divider obtains a radial position during rotation of approximately midway between the outer periphery of the rotor and the inner periphery of the stator. This radial position is preferably maintained by the hydrodynamic bearing action of the fluid within the gap, or alternatively through the use of radial positioning or retaining mechanisms. The use of axial constraint mechanisms to maintain the film divider within the air gap under the shear forces of the fluid during operation is also contemplated.

Abstract: A circuit to discriminate the source of harmonic distortion of the output voltage comprises voltage sensors coupled to the output terminals of a source of electric power and to a point of regulation remote from the source for sensing the output voltage waveform present at each of these locations. The circuit then utilizes these two sensed waveforms to discriminate the source of any harmonic distortion between the source of electric power and the utlization equipment. This circuit calculates the percentage total harmonic content of each of the sensed waveforms, and compares them to determine the source of distortion. If the percentage total harmonic content sensed at the point of regulation is greater than that sensed at the terminals of the source of electric power, the source of distortion is discriminated to be the utilization equipment; otherwise, the source of distortion is identified to be the source of electric power.

Abstract: An electric power generation system having two main sources of ac power comprises a first and a second main power conversion and distribution unit (MPCDU1, MPCDU2), each electrically coupled to one of the sources of ac power. The MPCDUs controllably supply ac electric power to an associated main distribution bus and additionally convert that power to a second type of power. This second type of power is supplied to an associated secondary distribution bus and to a converted power output. The system also includes an auxiliary source of ac power and an auxiliary power conversion and distribution unit (APCDU) which is electrically coupled to the auxiliary source. The APCDU controllably supplies ac electric power to a ground service distribution bus and additionally converts that power to a second type of power which is then supplied to an associated secondary distribution bus and to a converted power output.

Abstract: A multiple output synchronous generator in accordance with the instant invention comprises a stator having a first stator winding having a number of poles p and a second stator winding having a number of poles 2*p*n where p and n are any whole numbers, the first and second stator windings being wound utilizing a 60.degree. phase belt winding configuration such that the first stator winding is magnetically decoupled from the second stator winding preventing interaction therebetween. The generator additionally comprises a rotor rotatably disposed within the stator defining an airgap therebetween. The rotor has a first field winding of a first polarity and a second field winding having a second number of windings wound thereon for generating a flux across the airgap such that the flux induces a voltage in the first and second stator windings.

Abstract: A power transfer control system for use in an AC electric power generation system comprises a generator control unit (GCU) which senses and controls the output of a generator, and a bus power control unit (BPCU) which communicates with the GCU to control and coordinate a power transfer between the generator and another source. Each unit communicates power transfer information, which eliminates the requirement of redundant sensing circuitry and wiring for the BPCU. The BPCU transmits master power control information and a synchronizing signal indicating a zero phase reference point of a control waveform to which the power transfer will take place. The GCU compares parameters of the output power of its respective source with the master power control information and the synchronizing signal.

Abstract: A system and method of protection against the passive loss of differential current fault protection is provided for an electric power generating system (EPGS). The EPGS utilizes a bus power control unit (BPCU) to control and protect bus configuration, and a generator control unit to control each of the generators. This system and method protection protects against perpetuation of a bus fault on a left air vehicle distribution bus, a right air vehicle distribution bus, or a air vehicle tie bus during passive loss of normal differential current fault protection within the BPCU, and comprises circuitry for monitoring parameters of the generator output power, circuitry responsive to these parameters for detecting a high generator current condition for generating an output overload signal when the parameters indicate the presence of a bus fault.

Abstract: A quasi regulated electric generator, comprising a stator having teeth on an inner periphery defining slots therebetween, stator windings disposed in the slots forming output phases, a rotor rotatably mounted within the stator, the rotor having permanent magnets mounted thereon forming rotor poles which induce a voltage in the stator windings when the rotor is driven by an external prime mover, and a series saturation circuit coupled to an external source of dc current for saturating the stator, decreasing the induced voltage thereby. Magnetic slot closers are placed in the slots in which are disposed the series saturation circuit to aid tooth saturation.

Abstract: This invention relates to a method of combining a plurality of surface mount technology components and at least one plated through-hole component on a printed wiring board. The method includes applying to a secondary side of the printed wiring board a first layer of a preselected quantity of electrically conductive adhesive and then attaching a first portion of the plurality of the surface mount technology components to the adhesive. The first layer of the adhesive is then reflowed, thereby adhering the first portion of the plurality of surface mount technology components to the secondary side of the printed wiring board. The method then continues by applying to a primary side of the printed wiring board a second layer of the first preselected quantity of electrically conductive adhesive and applying to the primary side of the printed wiring board a second preselected quantity of electrically conductive adhesive.

Abstract: An impedance multiplier circuit comprises an input impedance having a certain value of impedance and a circuit coupled to this input impedance for multiplying its value by a multiplication factor. This multiplying circuit comprises a first and a second voltage follower amplifier and a first and a second scaling impedance. The input impedance is coupled between the input of the first voltage follower amplifier and the output of the second voltage follower amplifier with the first and second scaling impedances establishing a voltage division between the output of the first voltage follower amplifier and the input of the second voltage follower amplifier. In this way, the second voltage follower amplifier provides active negative feedback, and effectively multiplies the input impedances's impedance by a factor of one plus the quotient of the second scaling impedance to the first scaling impedance.

Abstract: An electric power generation and distribution system having a basic variable frequency distribution bus to which wide frequency variation tolerant utilization equipment is coupled and an enhanced frequency distribution bus to which wide frequency variation intolerant utilization equipment is coupled, comprises a variable speed generator driven by an external variable speed prime mover such as an aircraft engine. This generator produces output electric power having a frequency which varies with the speed at which the generator is driven. The system further comprises a converter which is electrically coupled to the generator and produces output electric power having a controlled frequency. A switching network operates to couple the generator to and decouple the converter from this enhanced bus when the frequency of the electric power produced by the generator is within a predetermined acceptable range to allow the generator to supply power thereto.

Abstract: An electric power distribution center for use on aircraft comprises a space frame having a first surface defining a plurality of sockets, and a second, generally parallel, surface defining a plurality of connector ports; a plurality of conducting bus bars utilizing a three dimensional routing configuration encapsulated within the space frame; current sensors integrally mounted within the space frame for monitoring the flow of electrical current through the conducting bus bars; and a printed circuit board encapsulated within the space frame for providing electrical circuit pathways within the power distribution center. Further, a plurality of load protection and control devices, seated within the sockets of the first surface, provide a switchable coupling between the bus bars and the printed circuit board to control the distribution of electric power to the individual aircraft loads.

Abstract: A mechanical gear drive system capable of generating electric power comprises a plurality of gears having a plurality of teeth separated by a tooth gap, a U-shaped core having two legs separated by at least one tooth gap, and a yoke. This core is positioned in close proximity to the teeth of the gear. A coil is wound on the yoke, and a converter selectively couples and decouples this coil from a dc power source. The converter has at least a first and a second switch and at least a first and a second diode for cross-coupling the coil to the source to allow current flow back when the switches are disabled. The converter enables the switches prior to alignment of the teeth of the gear with the legs of the core. This couples the coil to the source of dc power and allows dc current to flow from the source through the switches and the coil. When the converter disables the switches after alignment of the teeth with the legs, the coil is decoupled from said source.

Abstract: A control for an inverter having a switch which is operated in accordance with a PWM waveform having spaced rising and falling edges includes circuitry which detects the magnitude and polarity of a DC component in the AC output power produced by the inverter and an adder/subtractor which adjusts at least one of a rising and falling edge of the waveform to reduce the magnitude of the DC component.

Abstract: An electric power distribution center for use on aircraft comprises a space frame having a first surface defining a plurality of sockets, and a second, generally parallel, surface defining a plurality of connector ports; a plurality of conducting bus bars utilizing a three dimensional routing configuration encapsulated within the space frame; current sensors integrally mounted within the space frame for monitoring the flow of electrical current through the conducting bus bars; and a printed circuit board encapsulated within the space frame for providing electrical circuit pathways within the power distribution center. Further, a plurality of load protection and control devices, seated within the sockets of the first surface, provide a switchable coupling between the bus bars and the printed circuit board to control the distribution of electric power to the individual aircraft loads.

Abstract: An add-on distortion scrubber for use in an AC power generation system comprises an parallel connected inverter having a first DC link capacitor coupled in parallel, and a series connected inductive tie impedance. The inverter produces an output voltage having controllable magnitude, phase, and frequency components and operates by sensing the AC voltage waveform of the AC power generation system and controlling its output magnitude, phase, and frequency to fundamentally match the AC voltage waveform. In this way, the inverter appears as a virtual no-load to the AC power generation system while removing the harmonics therefrom. Alternatively, the scrubber inverter may be configured as a dedicated load filter by coupling it to the power input of the load. The scrubber inverter senses the total power delivered to the load/scrubber combination and generates an appropriate waveform to cancel the harmonics generated by the load.

Abstract: An electric power starter generator system comprises a synchronous generator and an induction motor/generator mutually coupled to a shaft being driven to an external prime mover. The synchronous generator and the induction motor/generator are driven by the shaft at the same speed. The system includes a rectifier/inverter having ac terminals coupled to the output of the induction motor/generator, and dc terminals coupled to a dc bus. This rectifier/inverter allows bi-directional power flow to effectuate both power generation as well as electric start of the prime mover. The synchronous generator is excited by a commonly driven permanent magnet generator and a modulated exciter field control. The induction motor/generator is self-exciting through the rectifier/inverter once a voltage is established on the dc bus. The establishment of this voltage may be accomplished by a battery, or by connection of the synchronous generator's output to the input of the rectifier/inverter through a poly-phase contactor.