公开(公告)号：US20200315071A1

公开(公告)日：2020-10-01

申请号：US16831886

申请日：2020-03-27

Applicant: ROLLS-ROYCE plc

Inventor： Chandana J. GAJAYAKE ,  Vivek MUTHU ,  Pradip CHATTERJEE ,  Amit K. GUPTA

IPC: H05K7/20 ,  F28D7/02 ,  B64D33/08

Abstract: 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.

公开(公告)号：US20190372494A1

公开(公告)日：2019-12-05

申请号：US16401570

申请日：2019-05-02

Applicant: ROLLS-ROYCE plc ,  MTU FRIEDRICHSHAFEN GMBH ,  MTU ONSITE ENERGY GMBH

Inventor： Yang SHICONG ,  Souvik DASGUPTA ,  Michael KREISSL ,  Johannes DEMHARTER ,  Amit K. GUPTA

IPC: H02P9/10 ,  H02P9/00 ,  H02K19/36

Abstract: A power system includes a synchronous electrical generator having a rotor driven by a shaft; a permanent magnet signaling generator, coupled to the shaft; and an angle computation unit configured to calculate a rotor angle or load angle based on a voltage from the permanent magnet signaling generator and a voltage from the synchronous electrical generator.

公开(公告)号：US20180100895A1

公开(公告)日：2018-04-12

申请号：US15705716

申请日：2017-09-15

Applicant: ROLLS-ROYCE plc

Inventor： Sivakumar NADARAJAN ,  Amit K. GUPTA ,  Vaiyapuri VISWANATHAN

IPC: G01R31/34 ,  G01M1/16 ,  G01H1/00

CPC classification number: G01R31/346 ,  G01H1/003 ,  G01H3/04 ,  G01H3/08 ,  G01M1/16

Abstract: There is disclosed a method for diagnosing a fault condition in an electric machine 4. The method comprises measuring S2 at least one physical parameter generated during operation of the electric machine 4; analysing S4 the or each measured parameter in a frequency domain; and determining S12 whether the electric machine 4 has a stator or rotor winding fault based on a comparison of an amplitude of the or each analysed parameter at a first predetermined frequency and a first threshold amplitude for the first frequency. The at least one physical parameter comprises a sound generated by the electric machine 4.

公开(公告)号：US20170170715A1

公开(公告)日：2017-06-15

申请号：US15348553

申请日：2016-11-10

Applicant: ROLLS-ROYCE plc

Inventor： Mohamed HM SATHIK ,  Chandana GAJANAYAKE ,  Sivakumar NADARAJAN ,  Bikramjit S. BHANGU ,  Amit K. GUPTA

IPC: H02M1/32 ,  H02H3/38 ,  H02H7/122 ,  H02M7/537

CPC classification number: H02M1/32 ,  H02H3/38 ,  H02H7/1227 ,  H02M7/537 ,  H02M7/53871

Abstract: A method of controlling an inverter, in which the inverter includes a single-phase inverter arrangement having a complementary pair of power switches, including the steps of: controlling the complementary pair of power switches with a modulating signal to output an AC signal; monitoring a collector-emitter voltage of each of the pair of power switches; if the collector-emitter voltage exceeds a predetermined value, the corresponding one of the pair of power switches is judged to be in a short circuit condition; and if either one of the pair of power switches is judged to be in a short circuit condition, executing a shutdown operation to switch off the corresponding one of the pair of power switches.

公开(公告)号：US20170160330A1

公开(公告)日：2017-06-08

申请号：US15347499

申请日：2016-11-09

Applicant: ROLLS-ROYCE plc

Inventor： Vaiyapuri VISWANATHAN ,  Sivakumar NADARAJAN ,  Amit K. GUPTA

IPC: G01R31/02 ,  H02P9/14

CPC classification number: G01R31/02 ,  G01R31/34 ,  H02P9/14 ,  H02P25/03 ,  H02P29/0241

Abstract: A rectifier diode failure detection apparatus for an electrical machine (10), the electrical machine (10) comprising an exciter armature winding (28a-c), a rotor main field winding (24) and first and second rectifiers (34a, 34b) arranged in parallel, each rectifier (34a, 34b) comprising at least first and second diodes (38a, 38b), each rectifier being configured to independently supply the rotor main field winding (24) with DC electrical current, the failure detection apparatus comprising:a controller (40) comprising at least two current sensors (42a, 42b), each current sensor (42a, 42b) being configured to measure output current (If1, If2) of a respective one of the rectifiers (34a, 34b), and the controller (40) being configured to determine a harmonic of the measured rectifier output currents; the controller (40) being further configured to determine a ratio of the magnitude of the first rectifier (34a) output current harmonic to the magnitude of the second rectifier (34b) output current harmonic, wherein the controller (40) is configured to determine that a fault has occurred in one of the rectifier diodes (38a, 38b) where the ratio exceeds a threshold value.