Rolls-royce Corporation

Jason E Hill

Seamus Dominic Garvey

Gareth Edward Moore

Alan J Mitcham

Stuart J Galloway

Patrick Norman

Steven D A Fletcher

Seamus D Garvey

Steven J Mountain

An electrical generating system for aircraft with one or more engines includes a plurality of generators associated with the engines so as to produce respective AC outputs. The frequencies of these outputs can differ from each other, as a result of differing engine speeds and/or deliberate design, but they are to be connected to a common bus to avoid redundancy of wiring. One or more converters are present between the generators and the bus for adjusting the output frequency of the generators to provide an AC output voltage at a common bus frequency. The system includes a control system for setting the AC bus frequency in such a way that it can vary with time. The bus frequency may follow the natural frequency of the engine, and only small converters are needed to make the already approximately equal generator frequencies identical, so that they can all feed the common bus.

Electrical distribution system

A protection system is provided for an electrical power network. The system has one or more circuit breaker arrangements which on activation isolate electrical faults within the network, and one or more fault detectors. The or each fault detector measures an inductance of a respective section of the network. The system is configured to activate one or more of the circuit breaker arrangements in response to measured inductances which are indicative of a fault.

Protection system for an electrical power network

This invention relates to a method of controlling torque oscillations in a mechanical drive train of an electrical generation system which provides electrical power to an isolated electrical network, the method including the steps of: a. monitoring for changes in the electrical condition of the electrical network; b. determining whether a change in the electrical condition of the network falls within a predetermined range; c. adjusting the power in the network using an auxiliary power source when the electrical condition of the network falls within the predetermined range so as reduce or substantially prevent the build up of torque oscillations in the mechanical drive train.

Method and apparatus for controlling torque on the shaft of a generator

A permanent magnet fault tolerant generator is driven by a variable speed shaft to create AC power at terminals , converted at to DC power before being applied to a load . The converter is a bi-directional device which rectifies AC to DC and also acts as an inverter to synthesize AC from the DC. This synthesized AC waveform is imposed on the terminals to maintain a constant magnitude generator output voltage, regardless of the speed of the shaft , and thus regardless of the EMF of the generator. This results in reactive currents flowing between the generator and the converter , but allows the generator design have a reduced current rating, resulting in improved generator size and weight.

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Newcastle-upon-Tyne, United Kingdom

Jason E Hill