GB1473837A - Electrical switchgear - Google Patents

Electrical switchgear

Info

Publication number
GB1473837A
GB1473837A GB4001373A GB4001373A GB1473837A GB 1473837 A GB1473837 A GB 1473837A GB 4001373 A GB4001373 A GB 4001373A GB 4001373 A GB4001373 A GB 4001373A GB 1473837 A GB1473837 A GB 1473837A
Authority
GB
United Kingdom
Prior art keywords
current
pulse
switch
signal
tripping
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.)
Expired
Application number
GB4001373A
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.)
UK Secretary of State for Defence
Original Assignee
UK Secretary of State for Defence
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 UK Secretary of State for Defence filed Critical UK Secretary of State for Defence
Priority to GB4001373A priority Critical patent/GB1473837A/en
Publication of GB1473837A publication Critical patent/GB1473837A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
    • H01H9/54—Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere
    • H01H9/56—Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere for ensuring operation of the switch at a predetermined point in the ac cycle
    • H01H9/563—Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere for ensuring operation of the switch at a predetermined point in the ac cycle for multipolar switches, e.g. different timing for different phases, selecting phase with first zero-crossing
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/22—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices
    • H02H7/222—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices for switches

Abstract

1473837 Arc extinguishing DEFENCE SECRETARY OF STATE FOR 2 Aug 1974 [23 Aug 1973] 40013/73 Heading H1N To ensure that the contacts of a vacuum switch will be fully open at the moment of initial arc extinction, the current is monitored by a detector with a monostable pulse generator arranged to provide an output pulse of predetermined duration to a coincidence gate when the current rises above a threshold value. If this pulse coincides with a tripping signal, contact separation will be initiated, the timing being such that contact separation will be completed when the current has reached zero. Three single phase switches 12-14 are mounted in the supply lines 6-8 and current is monitored by CTs 9-11, which feed through low pass filters 15- 17 and rectifiers 18-20 to threshold detectors 21-23 which are also fed with a reference current to act as comparators, this reference current being set at a value greater than the minimum are-sustaining current for the switch. Thus whenever the current through a line conductor rises through this threshold value the comparators will produce a signal pulse of predetermined duration through the monostable pulse generators 24-26. The duration of this pulse is such that there is sufficient time from its termination to the instant when the current falls again below the are-sustaining value for the switch contacts to open fully. This signal from the pulse generators is fed to AND gates 27-29 which also receive signals from any of the tripping sources associated with the switch-gear, so that if both signals coincide the switch in the associated line will be tripped. A monostable 30 may be inserted in the tripping signal line if there is a likelihood of the tripping signal being brief or intermittent. In a modification for simple systems wherein a substantially fixed load is to be connected into a relatively low impedance network, the current transformers are replaced by voltage transformers and the current is derived from the phase relationship.
GB4001373A 1974-08-02 1974-08-02 Electrical switchgear Expired GB1473837A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB4001373A GB1473837A (en) 1974-08-02 1974-08-02 Electrical switchgear

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4001373A GB1473837A (en) 1974-08-02 1974-08-02 Electrical switchgear

Publications (1)

Publication Number Publication Date
GB1473837A true GB1473837A (en) 1977-05-18

Family

ID=10412721

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4001373A Expired GB1473837A (en) 1974-08-02 1974-08-02 Electrical switchgear

Country Status (1)

Country Link
GB (1) GB1473837A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4628393A (en) * 1977-12-14 1986-12-09 Hazemeijer B.V. Method for switching in a three-phase high voltage circuit
DE3833166A1 (en) * 1988-09-27 1990-03-29 Siemens Ag Method for operating a power switch
WO1990003656A1 (en) * 1988-09-27 1990-04-05 Siemens Aktiengesellschaft Process for operating a power switch
WO2012136244A1 (en) * 2011-04-04 2012-10-11 Abb Technology Ag Fast breaker failure detection for hvdc circuit breakers

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4628393A (en) * 1977-12-14 1986-12-09 Hazemeijer B.V. Method for switching in a three-phase high voltage circuit
DE3833166A1 (en) * 1988-09-27 1990-03-29 Siemens Ag Method for operating a power switch
WO1990003656A1 (en) * 1988-09-27 1990-04-05 Siemens Aktiengesellschaft Process for operating a power switch
WO2012136244A1 (en) * 2011-04-04 2012-10-11 Abb Technology Ag Fast breaker failure detection for hvdc circuit breakers
US8947843B2 (en) 2011-04-04 2015-02-03 Abb Technology Ag Fast breaker failure detection for HVDC circuit breakers

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Legal Events

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