公开(公告)号：US11411390B2

公开(公告)日：2022-08-09

申请号：US17139393

申请日：2020-12-31

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Ritwik Chowdhury ,  Matchyaraju Alla ,  Satish Samineni ,  Normann Fischer ,  Dale S. Finney

IPC: H02H7/045 ,  H02H3/16 ,  G01R31/08 ,  H02H3/20 ,  H02H7/26

Abstract: Detection of, and protection against faults within a restricted earth fault (REF) zone of a transformer or a generator is disclosed herein. Security of the REF protection element uses comparison of a negative-sequence reference quantity. The REF condition is only detected when there is sufficient ground involvement and a fault in the reverse detection has not been detected. Dependability of the REF protection element in low-impedance grounded systems is improved by ensuring that the element operates when a zero-sequence reference quantity and a neutral operate quantity are orthogonal to each other. The REF protection element further determines an open CT condition and blocks detection of an REF fault upon determination of the open CT condition. A tripping subsystem may issue a trip command based upon detection of the REF condition.

公开(公告)号：US20220190581A1

公开(公告)日：2022-06-16

申请号：US17123450

申请日：2020-12-16

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Ritwik Chowdhury ,  Dale S. Finney ,  Normann Fischer ,  Matchyaraju Alla

IPC: H02H1/00 ,  G05B19/042 ,  G01R31/34 ,  G01R31/62 ,  H02H7/04

Abstract: The present disclosure relates to systems and methods for protecting against and mitigating the effects of over-excitation of elements in electric power systems. In one embodiment, a system consistent with the present disclosure may comprise a point pair subsystem to receive a plurality of point pairs that define an over-excitation curve for a piece of monitored equipment. The system may receive a plurality of measurements corresponding to electrical conditions associated with the piece of monitored equipment. A logarithmic interpolation subsystem may determine a logarithmic interpolation corresponding to one of the plurality of measurements based on the plurality of point pairs. An over-excitation detection subsystem may detect an over-excitation condition based on the logarithmic interpolation, and a protective action subsystem may implement a protective action based on the over-excitation condition.

公开(公告)号：US11316455B2

公开(公告)日：2022-04-26

申请号：US17003477

申请日：2020-08-26

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Matchyaraju Alla ,  Ritwik Chowdhury ,  Normann Fischer ,  Dale S. Finney ,  Rogerio Scharlach

IPC: H02P9/00 ,  G01R31/62 ,  G01R19/252 ,  H02P9/02

Abstract: Detection and protection against electric power generator rotor turn-to-turn faults, rotor multi-point-to-ground faults, and rotor permanent magnet faults is provided herein. A fractional harmonic signal is used to determine the rotor fault condition. The fractional harmonic signal may be a fractional harmonic magnitude of the circulating current of one phase. The fractional harmonic may be a fractional harmonic magnitude of a neutral voltage. A tripping subsystem may issue a trip command based upon detection of a rotor turn-to-turn fault condition.

公开(公告)号：US11233389B1

公开(公告)日：2022-01-25

申请号：US17085052

申请日：2020-10-30

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Ritwik Chowdhury ,  Gabriel Benmouyal

IPC: H02H9/00 ,  H02H3/04 ,  H02H7/04 ,  H01F27/42

Abstract: An intelligent electronic device (IED) may obtain a residual flux of each phase of a transformer. The IED may determine a maximum difference (DIF) signal based on the residual flux and the prospective flux associated with potential close POWs of the corresponding phase. The TED may select a closing POW that results in a minimum DIF signal. The TED may send a signal to close a ganged switching device of the transformer at a time based on the selected closing POW.

公开(公告)号：US10578653B2

公开(公告)日：2020-03-03

申请号：US15910226

申请日：2018-03-02

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Ritwik Chowdhury ,  Dale S. Finney

IPC: H02P9/00 ,  G01R19/165 ,  G01R19/25 ,  H02P9/10 ,  H02J3/44 ,  H02H7/045

Abstract: Disclosed are systems and methods to determine an overexcitation condition on electric power delivery system equipment that includes a magnetizing core. Overexcitation conditions are determined even during sub-synchronous resonance, ferro-resonance, and other complex events. Power system voltage is integrated and normalized to determine a flux on the magnetizing core. The flux is compared with a protection model to determine the overexcitation condition on the magnetizing core. Once an overexcitation condition is detected, a protective action may be taken to remove power from the effected power delivery system equipment.

公开(公告)号：US12249948B2

公开(公告)日：2025-03-11

申请号：US17823344

申请日：2022-08-30

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Ritwik Chowdhury ,  Matchyaraju Alla ,  Normann Fischer ,  Dale S. Finney

IPC: H02P9/00 ,  H02P103/20

Abstract: The present disclosure pertains to devices, systems, and methods for monitoring a generator. In one embodiment, the system may include a measurement subsystem to receive a plurality of split-phase measurements of branch currents associated with the at least one generator. A split-phase transverse differential monitoring subsystem may receive the plurality of split-phase measurements of branch currents associated with the at least one generator and may generate an offset value representing a standing split-phase current. A protective action subsystem may generate a first protective action based on the phasor operating current.

公开(公告)号：US20240097449A1

公开(公告)日：2024-03-21

申请号：US18459691

申请日：2023-09-01

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Ritwik Chowdhury ,  Douglas I. Taylor ,  Normann Fischer

IPC: H02J3/24 ,  H02H7/22 ,  H02J3/00 ,  H02J3/01

CPC classification number: H02J3/241 ,  H02H7/226 ,  H02J3/0012 ,  H02J3/00125 ,  H02J3/01

Abstract: The present application discloses systems and methods related to protection of a reactor in an alternating current (AC) electric power system. In one embodiment, a system may include a protective action subsystem to implement a protective action based on identification of a fault condition associated with a reactor. A frequency determination subsystem may determine when a frequency of the AC voltage is outside of a range defined by a lower threshold and an upper threshold and may identify a change in the frequency associated with de-energization of a line in electrical communication with the reactor. A supervisory subsystem may restrain implementation of the protective action when the frequency is outside of the range or when the change in the frequency is associated with de-energization of the line in electrical communication with the reactor.

公开(公告)号：US20220209525A1

公开(公告)日：2022-06-30

申请号：US17139393

申请日：2020-12-31

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Ritwik Chowdhury ,  Matchyaraju Alla ,  Satish Samineni ,  Normann Fischer ,  Dale S. Finney

IPC: H02H7/045 ,  H02H3/16

Abstract: Detection of, and protection against faults within a restricted earth fault (REF) zone of a transformer or a generator is disclosed herein. Security of the REF protection element uses comparison of a negative-sequence reference quantity. The REF condition is only detected when there is sufficient ground involvement and a fault in the reverse detection has not been detected. Dependability of the REF protection element in low-impedance grounded systems is improved by ensuring that the element operates when a zero-sequence reference quantity and a neutral operate quantity are orthogonal to each other. The REF protection element further determines an open CT condition and blocks detection of an REF fault upon determination of the open CT condition. A tripping subsystem may issue a trip command based upon detection of the REF condition.

公开(公告)号：US20210359503A1

公开(公告)日：2021-11-18

申请号：US16872636

申请日：2020-05-12

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Ritwik Chowdhury ,  Gabriel Benmouyal ,  Carolyn Sun

IPC: H02H3/02 ,  H02H1/00 ,  G05B17/02 ,  G05B9/02

Abstract: Systems and methods to estimate trapped charge for a controlled automatic reclose of a power line using a ganged switching device are described herein. For example, an intelligent electronic device (IED) may calculate a voltage amount associated with trapped charge of each phase of a power line based on voltage measurements of the power line. The IED may send a signal to close a ganged switching device at a time based at least in part on the trapped charge of each phase of a power line.

公开(公告)号：US10931097B2

公开(公告)日：2021-02-23

申请号：US16106538

申请日：2018-08-21

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Ritwik Chowdhury ,  Dale S. Finney

IPC: G01R31/34 ,  H02H7/06 ,  F01D15/10 ,  H02H3/52 ,  G01R31/50 ,  H02H3/08 ,  G01R19/25 ,  G01R21/00 ,  H02H3/16

Abstract: Detection of electric power generator stator ground fault conditions and protection of the generator due to such conditions is provided herein. In one embodiment, a generator protection element may calculate generator third harmonic voltage quantities using measurements from the generator terminals, and determine a stator ground fault condition using the calculated generator third harmonic voltage quantity. A tripping subsystem may issue a trip command based upon detection of a stator ground fault condition.