公开(公告)号：US09964600B2

公开(公告)日：2018-05-08

申请号：US14991139

申请日：2016-01-08

Applicant: ROLLS-ROYCE plc

Inventor： Chandana Jayampathi Gajanayake ,  Shantha Dharmasiri Gamini Jayasinghe ,  Sivakumar Nadarajan ,  Amit Kumar Gupta

IPC: G01R31/02 ,  G01R31/42

CPC classification number: G01R31/42

Abstract: A method of open-switch fault detection in a two-level voltage source power converter comprises the steps of: i. acquiring the waveforms of three-phase alternating current of the two-level voltage source power converter; ii. calculating at least a first time derivative of each acquired waveform; and iii. using the at least first time derivatives to determine whether an open-switch fault is present in the two-level voltage source power converter.

公开(公告)号：US10509078B2

公开(公告)日：2019-12-17

申请号：US14926853

申请日：2015-10-29

Applicant: ROLLS-ROYCE PLC

Inventor： Sivakumar Nadarajan ,  Shantha Dharmasiri Gamini Jayasinghe ,  Amit Kumar Gupta ,  Chandana Jayampathi Gajanayake ,  Viswanathan Vaiyapuri

IPC: G01R31/40

Abstract: A method of assessing a condition of a multi-phase power system comprises the steps of: acquiring a voltage signal and a current signal for each phase of the multi-phase power system; calculating a product of the voltage signal for each phase of the multi-phase power system with one of the current signals such that the product is between a voltage signal for one phase and a current signal for a different phase for at least two of the products; summing the calculated products; and identifying the possible existence of a fault in the multi-phase power system based on a frequency analysis of the summed calculated products.

公开(公告)号：US10267860B2

公开(公告)日：2019-04-23

申请号：US14626026

申请日：2015-02-19

Applicant: ROLLS-ROYCE PLC

Inventor： Subash C Athikessavan ,  Sivakumar Nadarajan ,  Amit Kumar Gupta ,  Sanjib K Panda

IPC: G01R31/00 ,  G01R19/165 ,  G01R31/34 ,  G01R31/02 ,  G01R31/06

Abstract: A method of detecting a fault in an induction machine having one or more windings arranged to draw current at a supply frequency, the method including: performing a process of judging whether a respective sideband of one or more selected harmonics of the supply frequency exists at a predetermined fault frequency in a signal in the one or more windings; and determining that a fault has occurred if the judgement is positive; wherein in the judging process each of the selected harmonics of the supply frequency is a harmonic frequency of the supply frequency other than the supply frequency itself.

公开(公告)号：US10605854B2

公开(公告)日：2020-03-31

申请号：US15596878

申请日：2017-05-16

Applicant: ROLLS-ROYCE plc

Inventor： Mohamed Halick Mohamed Sathik ,  Chandana Jayamapathi Gajanayake ,  Shantha Dharmasiri Gamini Jayasinghe ,  Amit Kumar Gupta ,  Rejeki Simanjorang

IPC: G01R31/26 ,  G01R31/327 ,  H02M3/158 ,  H02M7/217 ,  H02M7/537 ,  G01R31/40

Abstract: 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 ( dV dt ) across the switch; a rate of change of current ( di dt ) through the switch, a charge present on a gate of the switch (QG), a peak overshoot voltage (VPO) across the switch, and a peak overshoot or reverse recovery current (IRR) through the switch; and estimating the health of the switch based on the measured parameter(s).

公开(公告)号：US09910083B2

公开(公告)日：2018-03-06

申请号：US14573759

申请日：2014-12-17

Applicant: ROLLS-ROYCE PLC

Inventor： Vaiyapuri Viswanathan ,  Amit Kumar Gupta ,  Chandana Jayampathi Gajanayake ,  Sivakumar Nadarajan

IPC: G01R31/26 ,  G01R23/02 ,  G01R31/34 ,  G01R31/40 ,  H02H7/125 ,  H02K11/20

CPC classification number: G01R31/2632 ,  G01R23/02 ,  G01R31/343 ,  G01R31/40 ,  H02H7/1255 ,  H02K11/20

Abstract: A method of detecting a diode fault in an AC signal rectifier circuit, the AC signal rectifier circuit including a plurality of diodes, and being arranged to supply a rectified output voltage to a load, wherein the method includes the steps of deriving an operating value indicative of the ratio of the voltage magnitudes of a first harmonic frequency and another harmonic frequency of the rectified output voltage across the load; and determining whether a fault has occurred in one or more diodes on the basis of the derived operating value. The first harmonic frequency is preferably the fundamental harmonic frequency, and/or the another harmonic frequency is preferably the 6th harmonic frequency.