Rolls-Royce Corporation

Rollys-Royce Plc

Chandana Jayamapathi Gajanayake

Amit Kumar Gupta

Sivakumar Nadarajan

Pradip Chatterjee

Vaiyapuri Viswanathan

Rejeki Simanjorang

Vivek Muthu

Michael Adam Zagrodnik

Chao Bi

Shantha Dharmasiri Gamini Jayasinghe

Nay Lin Htun Aung

Sundararajan Prasanth

Mohamed Halick Mohamed Sathik

Mohamed H M Sathik

Jiang Quan

A two-start helical heat exchanger comprises a helical baffle extending along a length of the heat exchanger and having first and second surfaces, wherein: the first surface of the baffle is arranged to provide a first helical fluid flow path for a first fluid; and the second surface of the baffle is arranged to provide a second helical fluid flow path for a second fluid, wherein the second fluid flow path is arranged in counter-flow with the first fluid flow path and a casing within which the baffle is mounted. The baffle is arranged such that first and second fluid flow paths are in thermal contact with each other through the baffle, and in thermal contact with the casing. The heat exchanger may be incorporated into a power converter, for example to cool the power converter. The heat exchanger may be used on an aircraft.

Heat exchanger

A system, method and machine-readable instructions for monitoring a power electronics device. The system involves a semiconductor device, at least one sensor and a processor. The processor is configured to monitor a junction temperature of the semiconductor device by determining from the at least one sensor an on-state resistance of the semiconductor device and calculating the junction temperature of the semiconductor device according to a relationship between the on-state resistance of the semiconductor device and the junction temperature of the semiconductor device. The processor may apply an ageing coefficient to the on-state resistance.

Health monitoring and failure prognosis of power electronics devices

There is described a device for controlling an amount of current within a power distribution network by manipulating the amount of magnetic flux in the device and thus the impedance experienced by the power distribution network across the device. This is achieved by winding a plurality of coils about a magnetically permeable core and by providing the device with a magnetically permeable bridge element that is movable between a fully-open position at which the net magnetic flux generated in the core by alternating currents in each coil is zero, and a fully-closed position at which a net magnetic flux is present in the core.

Current controlling device

A method of classifying a stator winding fault in a brushless synchronous generator includes measuring an electrical parameter of the stator winding and classifying the fault by calculating positive or negative sequence harmonics of the parameter and comparing one or more harmonic component to a threshold.

Brushless synchronous generator stator winding fault

A thermal management device for dissipating heat from one or more electrical components in an aircraft, the thermal management device including: a heat spreader with a plurality of layers of annealed pyrolytic graphite, the heat spreader having higher thermal conductivity in a plane defined by the layers than in a direction perpendicular to the layers; a flow path for a cooling fluid defined through the heat spreader, such that at least a portion of the flow path is surrounded by the heat spreader, wherein the flow path is helical, around a central axis extending through the plurality of layers; and a housing encasing the heat spreader, the housing arranged to have one or more electrical components mounted there-on and to form a thermal interface between the heat spreader and one or more electrical components.

Thermal management device

A permanent magnet electrical machine has a rotor supporting a circumferential row of permanent magnets. The electrical machine further has a stator coaxial with the rotor and having a circumferential row of stator teeth carrying respective coils. The teeth provide paths for magnetic flux produced by the magnets, thereby electromagnetically linking the magnets and the coils when the rotor rotates relative to the stator. The teeth have respective core portions on which the coils are mounted, and respective tip portions located between the core portions and the rotor, neighbouring tip portions being circumferentially spaced from each other by respective gaps. Each pair of neighbouring tip portions has a bridge member and a thermal switching mechanism carried by a first tip portion of the pair.

Permanent magnet electrical machine

A method of monitoring the health of a semiconductor power electronic switch such as an insulated gate bipolar transistor (IGBT) is provided. The method having the steps of: measuring one or more parameters selected from the group consisting of: a rate of change of voltage across the switch; a rate of change of current through the switch, a charge present on a gate of the switch (Q), a peak overshoot voltage (V) across the switch, and a peak overshoot or reverse recovery current (I) through the switch; and estimating the health of the switch based on the measured parameter(s).

Method for estimating power system health

A fault condition is diagnosed in an electric machine that includes a rotor and a plurality of permanent magnets. To do so, the rotor is rotated so that each of the plurality of permanent magnets passes a magnetic flux density sensor, and the values of magnetic flux density are measured using the magnetic flux density sensor at a plurality of positions of the rotor. The measured values of magnetic flux density are analyzed and a magnitude of a peak amplitude is compared in a time or frequency domain with a reference value. If the peak amplitude is below the reference value, the electric machine is determined to have a fault condition.

Method and apparatus for diagnosing a fault condition in an electric machine

A method for detecting a fault in an exciter circuit, suitable for use in a brushless generator, the exciter circuit including (a) an exciter armature winding, having a plurality of armatures, arranged to generate a multiphase AC signal, each armature of the plurality of armatures providing a respective sub-signal component of the multiphase AC signal, and (b) a rectifier circuit for receiving the sub-signals via the respective armatures, the rectifier circuit comprising a plurality of components arranged to rectify the sub-signals to provide a rectified output signal, wherein the method includes the steps of: acquiring a respective operational sub-value for a first characteristic of each of at least two of the respective sub-signals; deriving an operational value indicative of a relationship between the acquired respective operational sub-values; determining whether a fault has occurred in the exciter circuit on the basis of the derived operational value.

Growing community of inventors

Singapore, Singapore

Chandana Jayamapathi Gajanayake