Rolls-royce Corporation

Lucas Industries Limited

Goodrich Control Systems Limited

Rollys-royce Plc

Simon Turvey

Keir Wilkie

Adrian Shipley

Fault-tolerant radial flux rotary electric machines are provided. One such machine comprises: a permanent magnet rotor having fourteen poles; and an alternate-wound stator having sixteen slots and four coil pairs, each coil pair forming part of one of four independent electrical phases.

Electric machines

An electrical machine has a stator with windings, first and second rotors, and an electrical output regulator. The first rotor carries alternating polarity first field magnets, such that, on drive mechanism rotation, the windings interact with the magnetic flux produced by the first magnets to create an EMF. The second rotor carries alternating polarity second field magnets, and has first and second rotational positions to reduce and increase, respectively, the magnetic flux energy. The electrical output regulator regulates a current from the windings to produce a torque on the rotors, as the drive mechanism increases from zero rotational speed, the torque rises above a threshold level that moves the second rotor from the first to the second rotational position, and, as the drive mechanism further increases the rotational speed, the torque peaks and then drops below the threshold level to move the second rotor back to the first rotational position.

Electrical machine

A switched reluctance generator and devices and methods for its control are concerned with generators and controls which can operate in an aerospace environment. The generator may have: a rotor having rotor poles; a stator having stator poles; and a controller. Either the rotor or stator poles each have windings to which current can be supplied to energise the poles and from which current can be drawn to a load; and the controller is arranged to: periodically excite each of the windings in turn to a pre-determined level of current; measure the current generated in each winding; cease the excitation when the current generated in each winding exceeds the excitation current; and direct the generated current in each winding to the load. The generator may thereby avoid the need to determine the position of the rotor poles relative to the stator poles to provide the commutation of the generator.

Generator and method for controlling a generator

A solid state power control apparatus includes: (a) at least one IGBT and at least one FET, for supplying current to a load, and (b) a current controller for shutting off the IGBT and FET. The current controller is arranged to start shut off of the IGBT before it starts shut off of the FET. Further, the current controller is arranged to reduce current flow prior to start of the turn off of the IGBT and FET.

Apparatus and method for solid state power control of current load

A switching circuit controls at least one semiconductor switch TR using drive signals generated from logic circuitry that generates complementary drive signals on an upper and lower drive path. Validation circuitry is provided between the logic circuitry and the semiconductor switch that inhibits any uncontrolled switching of the semiconductor switch TR due to noise, such as lightning strike, appearing at the load.

Switch control circuit

Solid state switching devices, such as power IGBT's, are used to switch a load from one AC generator to another. The switching is controlled to occur only when the phase and voltage of the two generator outputs are within acceptable limited, thus minimizing voltage and current transients.

Power transfer system

A contactor includes a switching circuit for switching a load between one or more electrical supplies, a current detector for detecting the current flowing through the load, a trip circuit for tripping the current after an interval of time which depends upon how much the current flowing through the load exceeds a predetermined amount, and a pre-trip circuit for providing an indication during said time interval that the current exceeds said predetermined amount for providing 'pre-trip' or 'near-trip' information.

Contactor and trip circuit therefor

A power switching circuit includes first and second semiconductor switches providing parallel paths connecting a load across a power supply. A circuit maintains the second switch in an off state except when the current in the first switch exceeds a predetermined value.

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Birmingham, United Kingdom

Simon Turvey