公开(公告)号：US20210067072A1

公开(公告)日：2021-03-04

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 ,  H02P9/02 ,  G01R31/62 ,  G01R19/252

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：US20230333153A1

公开(公告)日：2023-10-19

申请号：US18301713

申请日：2023-04-17

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Kanchanrao Gangadhar Dase ,  James Burton Colwell ,  Matchyaraju Alla ,  Shreenivas Pai

IPC: G01R31/08 ,  G01R19/165

CPC classification number: G01R31/085 ,  G01R19/16571

Abstract: Disclosed herein are systems for determining a broken conductor condition in a multiple-phase electric power delivery system. It has been observed that broken conductors pose a safety concern when occurring in the presence of people or vulnerable environmental conditions. Broken conductor conditions disclosed herein may be used to detect and trip the phase with the broken conductor, thus reducing or even eliminating the safety risk. Broken conductors may be determined using detected phase series arcing differences in one phase without commensurate differences in other phases. In various embodiments the phase series arcing attributes may be phase current monitored for decrement and/or phase resistance monitored for increase.

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：US20210184607A1

公开(公告)日：2021-06-17

申请号：US16717438

申请日：2019-12-17

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Matchyaraju Alla

IPC: H02P9/00 ,  H02P9/02

Abstract: A generator system includes a generator including terminals, a generator circuit breaker coupled to the terminals and that couples and decouples the generator from a power grid, multiple sensors, and a controller that operates the generator system. The controller determines whether an active power is less than a reverse active power threshold and whether one or more turbine valves are closed, and determines that a breaker failure has occurred based on the active power being less than the reverse active power threshold and the one or more turbine valves being closed. If the active power remains less than the reverse active power and the turbine valves remain closed after a threshold time period after the trip command, and if a reactive power is less than a reverse reactive power threshold, then a breaker failure has occurred. In response, the controller may transmit another trip command to the generator circuit breaker to initiate the breaker failure protection.