GB2008345A - Monitoring polyphase currents - Google Patents

Monitoring polyphase currents

Info

Publication number
GB2008345A
GB2008345A GB7844490A GB7844490A GB2008345A GB 2008345 A GB2008345 A GB 2008345A GB 7844490 A GB7844490 A GB 7844490A GB 7844490 A GB7844490 A GB 7844490A GB 2008345 A GB2008345 A GB 2008345A
Authority
GB
United Kingdom
Prior art keywords
multiplexed signal
comparing
detected
unbalance
threshold
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB7844490A
Other versions
GB2008345B (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Multilin Inc
Original Assignee
Multilin Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Multilin Inc filed Critical Multilin Inc
Priority to GB7844490A priority Critical patent/GB2008345B/en
Publication of GB2008345A publication Critical patent/GB2008345A/en
Application granted granted Critical
Publication of GB2008345B publication Critical patent/GB2008345B/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
    • H02H3/083—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current for three-phase systems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass
    • H02H3/162—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass for ac systems
    • H02H3/165—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass for ac systems for three-phase systems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
    • H02H3/32—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
    • H02H3/34—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors of a three-phase system

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

To monitor polyphase currents, phase signals representative of the current in each phase are time- division multiplexed (18) so as to obtain a single multiplexed signal, and the multiplexed signal then processed to extract from it an output signal or signals representative of, for example, short circuit, overload, unbalance or earth fault conditions. Short circuits are detected by comparing (36) the instantaneous value of the rectified multiplexed signal with a threshold, and overloads by comparing (52) the average value (46) with a threshold. Unbalance is detected by comparing (42) the instantaneous and average values. Earth faults are detected by sensing (60, 64) any mains-frequency component in the unrectified multiplexed signal. <IMAGE>
GB7844490A 1977-11-14 1978-11-14 Method of and apparatus for monitoring polyphase currents Expired GB2008345B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB7844490A GB2008345B (en) 1977-11-14 1978-11-14 Method of and apparatus for monitoring polyphase currents

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB4736677 1977-11-14
GB7844490A GB2008345B (en) 1977-11-14 1978-11-14 Method of and apparatus for monitoring polyphase currents

Publications (2)

Publication Number Publication Date
GB2008345A true GB2008345A (en) 1979-05-31
GB2008345B GB2008345B (en) 1982-08-18

Family

ID=26266028

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7844490A Expired GB2008345B (en) 1977-11-14 1978-11-14 Method of and apparatus for monitoring polyphase currents

Country Status (1)

Country Link
GB (1) GB2008345B (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0022952A1 (en) * 1979-07-23 1981-01-28 Siemens Aktiengesellschaft Filter input protection
EP0046024A1 (en) * 1980-08-11 1982-02-17 South Eastern Electricity Board Earth leakage current breaker
FR2509098A1 (en) * 1981-07-02 1983-01-07 Carrier Corp ALTERNATING CURRENT MOTOR PROTECTION DEVICE
EP0075873A1 (en) * 1981-09-30 1983-04-06 Kabushiki Kaisha Toshiba Protective relay system
EP0082103A1 (en) * 1981-11-02 1983-06-22 Asea Ab Method and arrangement for realising the detection of earth faults in an electric-energy distribution network
EP0092620A1 (en) * 1982-04-28 1983-11-02 Hitachi, Ltd. Protective relay
EP0040471B1 (en) * 1980-05-20 1985-10-02 Kabushiki Kaisha Toshiba Protective relaying system
GB2231216A (en) * 1989-04-05 1990-11-07 Mitsubishi Electric Corp Zero-phase sequence imbalance current detector
WO1998013921A1 (en) * 1996-09-24 1998-04-02 Siemens Aktiengesellschaft Circuit arrangement for detection of current in an electric conductor to control electronically controllable tripping devices
WO2011032585A1 (en) * 2009-09-16 2011-03-24 EMAC (Electromechanical Applications Consulting) Limited Apparatus for protecting a medium voltage distribution transformer and the distribution line upstream of the transformer

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0022952A1 (en) * 1979-07-23 1981-01-28 Siemens Aktiengesellschaft Filter input protection
EP0040471B1 (en) * 1980-05-20 1985-10-02 Kabushiki Kaisha Toshiba Protective relaying system
EP0046024A1 (en) * 1980-08-11 1982-02-17 South Eastern Electricity Board Earth leakage current breaker
FR2509098A1 (en) * 1981-07-02 1983-01-07 Carrier Corp ALTERNATING CURRENT MOTOR PROTECTION DEVICE
EP0075873A1 (en) * 1981-09-30 1983-04-06 Kabushiki Kaisha Toshiba Protective relay system
EP0082103A1 (en) * 1981-11-02 1983-06-22 Asea Ab Method and arrangement for realising the detection of earth faults in an electric-energy distribution network
EP0092620A1 (en) * 1982-04-28 1983-11-02 Hitachi, Ltd. Protective relay
GB2231216A (en) * 1989-04-05 1990-11-07 Mitsubishi Electric Corp Zero-phase sequence imbalance current detector
US5159561A (en) * 1989-04-05 1992-10-27 Mitsubishi Denki Kabushiki Kaisha Zero-phase sequence current detector
GB2231216B (en) * 1989-04-05 1993-04-14 Mitsubishi Electric Corp Zero-phase sequence current detector
WO1998013921A1 (en) * 1996-09-24 1998-04-02 Siemens Aktiengesellschaft Circuit arrangement for detection of current in an electric conductor to control electronically controllable tripping devices
US6147847A (en) * 1996-09-24 2000-11-14 Siemens Aktiengesellschaft Circuit arrangement for detecting the current of a current conductor in order to activate electronically controllable tripping devices
WO2011032585A1 (en) * 2009-09-16 2011-03-24 EMAC (Electromechanical Applications Consulting) Limited Apparatus for protecting a medium voltage distribution transformer and the distribution line upstream of the transformer

Also Published As

Publication number Publication date
GB2008345B (en) 1982-08-18

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee