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May 9, 2020 15:05
4 yrs ago
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English term
selectivity trip time-delay
English to French
Tech/Engineering
Electronics / Elect Eng
(in a patent) PROTECTION SYSTEM HAVING REDUCED ENERGY LET-THROUGH MODE AND ZONE SELECTIVITY
said first circuit breaker (14) configured to provide a selectivity trip time-delay
The field of the invention relates generally to power distribution systems and more particularly, to a method and system for a circuit protection system providing dynamic delay times for circuit breakers throughout the system.
Conventional circuit breakers often employ microprocessor-based digital solid-state trip units to generate an inverse time long delay and/or short delay trip such as by digital simulation of the heating and cooling of a bimetallic strip
ZSI utilizes upstream circuit breakers having pre-programmed time delays so that the downstream circuit breakers are provided with an opportunity to clear the fault without intentional delay before the upstream circuit breaker opens or trips.
in a conventional ZSI system, if a feeder circuit breaker is in pick-up and is set
with normal mode trip time delay of 58ms, then a sub-main circuit breaker directly
upstream from the feeder circuit breaker will be set with a time-delay of the feeder circuit breaker’s normal mode trip time-delay increased by 100ms of zone selectivity delay (i.e., 158ms total delay). Similarly, a main breaker directly upstream from the sub-main circuit breaker will be set with the feeder circuit breaker’s trip time-delay (58ms) increased by the first tier sub-main selectivity delay (100ms), plus an additional 100ms of the second tier main circuit breaker selectivity delay, for a total trip time-delay of 258ms.
The field of the invention relates generally to power distribution systems and more particularly, to a method and system for a circuit protection system providing dynamic delay times for circuit breakers throughout the system.
Conventional circuit breakers often employ microprocessor-based digital solid-state trip units to generate an inverse time long delay and/or short delay trip such as by digital simulation of the heating and cooling of a bimetallic strip
ZSI utilizes upstream circuit breakers having pre-programmed time delays so that the downstream circuit breakers are provided with an opportunity to clear the fault without intentional delay before the upstream circuit breaker opens or trips.
in a conventional ZSI system, if a feeder circuit breaker is in pick-up and is set
with normal mode trip time delay of 58ms, then a sub-main circuit breaker directly
upstream from the feeder circuit breaker will be set with a time-delay of the feeder circuit breaker’s normal mode trip time-delay increased by 100ms of zone selectivity delay (i.e., 158ms total delay). Similarly, a main breaker directly upstream from the sub-main circuit breaker will be set with the feeder circuit breaker’s trip time-delay (58ms) increased by the first tier sub-main selectivity delay (100ms), plus an additional 100ms of the second tier main circuit breaker selectivity delay, for a total trip time-delay of 258ms.
Proposed translations
(French)
4 -1 | temps de déclenchement de sélectivité | Marcombes (X) |
4 -1 | téléruption temporisée | Samuel Clarisse |
Proposed translations
-1
1 hr
temps de déclenchement de sélectivité
"Le premier mode prévoit des temps de déclenchement de sélectivité avec les disjoncteurs haute tension".
Peer comment(s):
disagree |
Tony M
: The 'retard de déclenchement' is quite distinct from the 'temps de déclenchement', which is the intrinsic delay in operation. / No, this is quite clearly the deliberate ADDED time delay, otherwise it would say 'trip time' — EN usage is quite precise here
46 mins
|
Il s'agit du temps ici et non pas du retard. Le temps de déclenchement d'un disjoncteur, le temps qu'il met pour couper le courant, n'est pas négligeable de l'ordre de 10-20 ms pour la basse tension.
|
-1
2 hrs
téléruption temporisée
Peer comment(s):
disagree |
Tony M
: From the context we have available, this doesn't seem to be describing any form of 'télérupteur', and you have omitted the vital 'selectivity' / Not at all: = 'discrimination' in FR = ability to discr. between different fault locations.
12 mins
|
"Selectivity" dans le sens de "sélectionner ou choisir" non ? Ce que fait une téléruption...
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Discussion
But if each stage of the tree structure has to be protected by a device capable of carrying the sum of all the downstream devices (as would seem logical), going back up the line, you'd need some wildly over-rated supplies, cabling, etc.!
But of course, not all devices are on all the time and/or always drawing their maximum current; hence ratings can be reduced to more practical levels; but all this requires terribly careful management of the trip settings and methods of controlling the overload / delay characteristic — which the devices being patented here are seemingly intended to facilitate.
In an industrial electrical scenario, there may be a whole string of protective devices in a dendritic structure betwwen [Power source] and [terminal device consuming power]
The purpose of selectivity (usually called 'discrimination' in FR, and sometimes even in EN! The exact difference between these terms seems to be rather unclear, and is explained differently depending on which equipment manufacturer you read) is to ensure that in the event of a fault's occurring, the ideal situation is that ONLY the circuit-breaker (etc.) immediately upstream of the device will trip — thus avoiding the situation where the whole factory is plunged into darkness because the tea-room kettle blew up!
This ia a very delicate game, to ensure adequate, fast protection, while avoiding waiting too long with catastrophic consequences where fault currents may be in the kA range! As the sources text starts by explaining...
'time-delay' here is probably 'temporisation' (sometimes may be 'retard')
'selectivity' is usually 'discrimination' (there seems to be a lot of confusion about these 2 terms in FR literature!)
The problem is, I've never come across this exact collocation before, so can't be sure how best to handle it; the way I understand it is 'time-delay before tripping for the purpose of discrimination' — I understand exactly what they are talking about, but just can't quite work out the best way to put all the elements together!
It may help to look in the rest of your document to check just how this works; in particular, if this is adjustable (preset) or dynamically modified (which is part of what they start describing).