Patent application number | Description | Published |
20090229847 | Earthing arrangement for a DC electrical system and a method of operating an earthing arrangement for a DC electrical system - An earthing arrangement for a DC electrical system ( | 09-17-2009 |
20090292488 | ELECTRICAL DISTRIBUTION NETWORKS - Safe operation of electrical power distribution systems necessitates consideration of the fault level in terms of the potential for electrical current flow upon an earth or other fault within the electrical power distribution system. Previously, electrical power systems have been analysed to provide theoretical fault levels values for different zones of an electrical power distribution system based upon a worse case scenario. However, existing electrical loads will in practice provide a more adaptable and higher fault level. By monitoring and identifying an I-V characteristic upon switching electrical load in practical operation an actual default level at particular nodes in a power distribution system is determinable. In such circumstances decisions with regard to the connectablilty of further electrical generators or loads at particular parts and zones of an electrical power distribution system can be quantified by reference to the actual fault level rather than the theoretical worse case scenario level and therefore avoid unnecessary upgrading of transmission equipment or denying access to the electrical power system. | 11-26-2009 |
20100024434 | Gas turbine engine arrangement - A gas turbine engine arrangement ( | 02-04-2010 |
20100033141 | Generating system - Within generator systems maintenance of stability in terms of voltage is desirable. Generally, several generators will be arranged in parallel within the generator system with one generator voltage controlled to provide dynamic responsiveness to load switching. With regard to some loads which are generally of an active nature, the capacity of a first generator, which is voltage controlled, may be insufficient to adequately avoid transient voltage instability. By providing an actuator signal from a load to act as a pre-emptive or forward feed to an electrical current controlled generator, that second electrical current generator can be arranged to provide additional or reduced electrical current to avoid system voltage instability. | 02-11-2010 |
20100038969 | Method and system for electrical power generation - Electrical power generation systems typically comprise an electrical power distribution arrangement in which a number of electrical power generators are coupled in parallel. In such circumstances in order to avoid conflict generally a first electrical power generator is controlled with a voltage controller whilst second electrical power generators have electrical current controllers. As loads are switched into and out of the electrical distribution system in normal operation the first electrical power generator and its voltage controller can accommodate voltage dynamics and therefore maintain a desired voltage. However, in order to accommodate heavier loads switching, the dynamic operation of the electrical current controller is achieved through utilising operational voltage margins from a desired voltage as control signals to the electrical current controller. A threshold is provided above which the electrical voltage margin must operate and regimes are provided to determine continued increase or fall in the operational voltage to allow continued dynamic control of the electrical current in order that voltage stability can be re-established with regard to electrical power distribution arrangements. | 02-18-2010 |
20100039075 | Electrical power arrangement - Utilisation of a number of electrical machines such as generators all driven by a common prime mover, such as a gas turbine engine, are known. However, faults in one phase of one particular electrical machine may cause torque vibration and therefore stressing to mechanical linkages between the electrical machine and the prime mover. By determining torque vibration and then utilising a second electrical machine to introduce an anti-phase torque vibration a substantially balanced and steady torque loading to the mechanical linkages can be achieved. | 02-18-2010 |
20100039076 | Electromechanical arrangement - Electromechanical arrangements are utilised widely whereby a prime mover in the form of a mechanical assembly such as a gas turbine engine is utilised to drive an electrical machine as an electrical generator. Unfortunately the loads applied to the electrical generator may vary creating oscillation across phases of the electrical generator. Such oscillations generally will be translated to the mechanical assembly in the form of torque oscillations which may cause stressing. Stressing of the mechanical assembly will reduce its life and may alter its performance as well as fuel consumption. By provision of appropriate mechanisms for balancing electrical loads across an electrical machine as well reducing the time decay period for stored charge within an electrical assembly associated with an electrical machine it is possible to reduce torque oscillations as presented to the mechanical assembly and therefore improve its operational performance. | 02-18-2010 |
20100039741 | Electrical protection arrangement for an electrical distribution network - Electrical distribution networks ( | 02-18-2010 |
20100045221 | Electrical machine arrangement - Electrical machine arrangements have advantages with regard to providing local electrical power and starting. Embedding such electrical machine arrangements in machinery such as gas turbine engines is advantageous in removing mechanical linkages and reducing aerodynamic drag. However, the components utilised must be able to withstand harsh environmental conditions and therefore the DC link capacitor used for smoothing of voltage fluctuations are limited to relatively low capacitance densities. Low density DC link capacitors require large sizes which render electrical machines less acceptable for embedded usage. By providing offset of electrical current in inductance elements such as stator windings and stator coils of electrical machines in dead periods of the cycle a reduction in DC link capacitor requirements is achieved reducing the size, weight and complexity of installing electrical machines in gas turbine engines. | 02-25-2010 |
20100046125 | FAULT CURRENT LIMITING - An alternating current system | 02-25-2010 |
20100117569 | SYNCHRONOUS ELECTRICAL MACHINE - A synchronous electrical machine comprising a plurality of phases, detecting means arranged to detect a fault in at least one of the phases of the synchronous electrical machine, isolating means arranged to isolate the at least one phase of the synchronous electrical machine with the fault, phase shift means arranged to produce a controlled phase shift between the voltage and the current within the remaining phases of the synchronous electrical machine to adjust the phase angle and magnitude of the second harmonic powers produced by the remaining phases of the synchronous electrical machine such that the vector sum of the second harmonic power vectors of the remaining phases of the synchronous electrical machine is zero. | 05-13-2010 |
20100252691 | AIRCRAFT ELECTRICAL ACTUATOR ARRANGEMENT - An aircraft ( | 10-07-2010 |
20110080000 | SYNCHRONOUS ELECTRICAL MACHINE - A synchronous electrical machine comprises a plurality of phases and detecting means arranged to detect an open-circuit fault in at least one of the phases of the synchronous electrical machine. Isolating means is arranged to isolate the at least one phase of the synchronous electrical machine with the fault. Phase shift means are arranged to produce a controlled phase shift between the voltage and the current within the remaining phases of the synchronous electrical machine so as to adjust the phase angle of the second harmonic powers produced by the remaining phases of the synchronous electrical machine such that the vector sum of the second harmonic power vectors of the remaining phases of the synchronous electrical machine is zero to eliminate torque ripple. The phase shift means is arranged to adjust the phase angle of all the remaining phases by the same predetermined angle to maximise the torque ripple-free power output of the synchronous electrical machine. | 04-07-2011 |
20110254274 | GAS TURBINE ENGINES - The generator uses a permanent magnet electrical machine providing three phase, unregulated DC voltage, from three windings feeding a rectifier circuit. A capacitor across the DC voltage acts as a buffer between the DC supply and the load. Regulation of the DC supply seen by the load is achieved by a switch in parallel with the DC voltage and with the load. The switch allows current to be drawn by the capacitor or load from the windings, or shorts the windings. The inductance of the windings makes it safe to short them. A blocking diode prevents current returning from the capacitor when the switch is closed. The result is a regulated DC output of adequate quality for e.g. aerospace applications and with low component count and complexity. | 10-20-2011 |
20110254284 | ELECTRICAL GENERATION - Synchronous generators are driven by shafts to produce 3-phase AC power. The frequency and amplitude of power depends on the speed of the respective shaft. The outputs are rectified and connected in series to provide an output of varying voltage DC power to a load. Applications in aerospace and renewable energy supply are described. | 10-20-2011 |
20120104847 | DISTRIBUTED POWER GENERATION - Distributed power generation systems generally include a number of power sources and electrical power loads interconnected by a distribution network. Electrical switches and fuses are provided such that local groups of power sources and power loads can be established. Should there be a degradation in the distribution network in terms of a set of criteria such as electrical frequency, current or voltage then the switch or fuse may be thrown to establish each local group as an island. By monitoring divergence from a set of criteria a method and controller may be utilised whereby the distribution network as a whole is considered and configured to establish virtual islands which operate prior to the establishment whether inadvertently or deliberately of actual islands within the distribution network. In such circumstances the transition from normal operation for the distribution network to islanded operation for the distribution network is less severe | 05-03-2012 |