公开(公告)号：US20210143634A1

公开(公告)日：2021-05-13

申请号：US17078842

申请日：2020-10-23

Applicant: Rolls-Royce plc

Inventor： Devinda A. Molligoda ,  Chandana J. Gajanayake ,  Pradip Chatterjee ,  Amit K. Gupta

IPC: H02H9/02 ,  H02M1/36

Abstract: The present disclosure concerns a current limiting circuit for a power converter, which may be used to limit charge and discharge currents for electrical power storage units. In an example embodiment, a current limiting circuit comprises: first and second field effect transistors, each having source, gate and drain connections, wherein the source connection of the first transistor is connected to the gate connection of the second transistor and the source connection of the second transistor is connected to the gate connection of the first transistor; and a resistor connected between the source connections of the first and second transistors, wherein drain connections of the first and second transistors are connectable between a DC electrical power supply and an electrical load for limiting a maximum current flowing between the electrical power supply and the electrical load.

公开(公告)号：US20240192263A1

公开(公告)日：2024-06-13

申请号：US18523453

申请日：2023-11-29

Applicant: ROLLS-ROYCE PLC

Inventor： Mohamed Sathik MOHAMED HALICK ,  Sivakumar Nadarajan ,  Viswanathan Vaiyapuri ,  Amit K. Gupta

IPC: G01R31/27 ,  G01R31/26

CPC classification number: G01R31/27 ,  G01R31/2621

Abstract: A method of monitoring a health state of a power semiconductor device includes: receiving an initial transient voltage parameter relating to transient voltage of the power semiconductor device when turning on, when it is known to be unaged; receiving an initial transient current parameter relating to transient current of the power semiconductor device when turning on, when it is known to be unaged; determining an initial energy parameter, relating to initial turn-on switching energy or power of the power semiconductor device, when it is known to be unaged; receiving an operating transient voltage parameter relating to the transient voltage of the power semiconductor device in operation; receiving an operating transient current parameter relating to the transient current of the power semiconductor device in operation; determining an operating energy parameter; and determining the health state of the power semiconductor device based on the initial energy parameter and the operating energy parameter.

公开(公告)号：US11412642B2

公开(公告)日：2022-08-09

申请号：US16831886

申请日：2020-03-27

Applicant: ROLLS-ROYCE plc

Inventor： Chandana J. Gajanayake ,  Vivek Muthu ,  Pradip Chatterjee ,  Amit K. Gupta

IPC: H05K7/20 ,  B64D33/08 ,  F28D7/02 ,  F28D7/00 ,  F28F7/02 ,  F28D21/00

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：US10408879B2

公开(公告)日：2019-09-10

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 ,  G01H1/00 ,  G01M1/16 ,  G01H3/04 ,  G01H3/08

Abstract: A method for diagnosing a fault condition in an electric machine includes measuring at least one physical parameter generated during operation of the electric machine; analyzing the or each measured parameter in a frequency domain; and determining whether the electric machine has a stator or rotor winding fault based on a comparison of an amplitude of the or each analyzed parameter at a first predetermined frequency and a first threshold amplitude for the first frequency. The at least one physical parameter includes a sound generated by the electric machine.

公开(公告)号：US11248966B2

公开(公告)日：2022-02-15

申请号：US16437371

申请日：2019-06-11

Applicant: ROLLS-ROYCE plc

Inventor： Mohamed H. M. Sathik ,  Rejeki Simanjorang ,  Chandana J. Gajanayake ,  Sundararajan Prasanth ,  Amit K. Gupta

IPC: G01K7/00 ,  G01K3/00 ,  G01K1/00 ,  G01K7/16 ,  H02P29/60 ,  G01K7/01 ,  H02P29/024

Abstract: 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.

公开(公告)号：US10082531B2

公开(公告)日：2018-09-25

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 ,  G01R31/34 ,  H02P29/024

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.

公开(公告)号：US10038367B2

公开(公告)日：2018-07-31

申请号：US15601050

申请日：2017-05-22

Applicant: ROLLS-ROYCE plc

Inventor： Xiong Liu ,  Michael A. Zagrodnik ,  Amit K. Gupta

IPC: H02M1/42 ,  H02M7/04 ,  H02P7/03 ,  H02M7/66 ,  H02M7/84 ,  H02M5/458 ,  H02M7/49

CPC classification number: H02M1/4233 ,  H02M1/4216 ,  H02M5/4585 ,  H02M7/49 ,  H02M7/66 ,  H02M7/84 ,  H02M2001/4283 ,  H02P7/04 ,  Y02B70/126

Abstract: An electrical system including a three phase AC input supply and three or more H-bridge converter cells. Each H-bridge converter cell has: an active front end rectifier for receiving the three phase AC input supply and transforming it into a DC supply, thereby providing a rectifier current ii; a capacitor suitable to receive a capacitor current iC, the capacitor smoothing the DC supply; and an inverter suitable to receive an inverter current io, wherein io=ii−iC, said inverter transforming the received inverter current io into a single phase AC supply. The system also including a control subsystem, which provides a signal to each active front end rectifier to vary its respective rectifier current ii such that the difference between the rectifier current ii, provided by the active front end rectifier, and the inverter current io, received by the inverter, is substantially zero.