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reactive volt amperes
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Glossary entry

English term or phrase:

FIELD GROUND (field winding ground detector)

French translation:

détecteur de fuite à la terre (relais à détection de fuite à la terre)

Added to glossary by Johannes Gleim
May 19, 2018 09:46
6 yrs ago
8 viewers *
English term

FIELD GROUND

English to French Tech/Engineering Electronics / Elect Eng
FIELD GROUND DETECTOR - The field ground detector consist of two parts.
A rotating transmitter and stationary receiver.
The rotating transmitter lights 8 LEDs when there is no field ground.
When a field ground occurs the stationary receiver detects the loss of light and initiates a timer before a fault alarm and/or trip is produced
Proposed translations (French)
4 détecteur de fuite à la terre (relais à détection de fuite à la terre)
3 +2 (détecteur) de défaut d'isolement
3 +1 (dispositif de détection) de fuites à la masse de la bobine d'excitation
Change log

May 19, 2018 09:46: changed "Kudoz queue" from "In queue" to "Public"

May 24, 2018 09:44: Johannes Gleim Created KOG entry

May 24, 2018 09:46: Johannes Gleim changed "Edited KOG entry" from "<a href="/profile/35790">Johannes Gleim's</a> old entry - "FIELD GROUND"" to ""détecteur de fuite à la terre (relais à détection de fuite à la terre) ""

Discussion

Johannes Gleim May 21, 2018:
As we have exchanged a lot of information, sometimes confusing, I think it’s useful to resume all fact and deductions.

We obviously deal with a synchronous generator or alternator. Such machines normally have a field winding (or excitation winding) in its stator or rotor carcass. A field is no material matter, but a field winding is it. I was first puzzled about "field", but as Tony added "windings", I remembered that this is an material and essential part of synchronous generators.

The term "MACHINE FIELD GROUND DETECTOR RELAY" should therefore been read as "MACHINE FIELD WINDING GROUND DETECTOR RELAY". The main term is again "GROUND DETECTOR RELAY", what I understand as ground/earth leakage detector/monitor/relay. The term " FIELD WINDING" is the determiner only and " MACHINE" refers to the complete generator unit. The detector may be a relay of type PJ11E/PJ11F and mounted on or in a control panel outside the machinery as described in the relevant GE article. The ground leakage signals may be transmitted from the carcass via rotating transformers and ArcNet to the control panel. More details are provided in the annex to my proposal.
Tony M May 20, 2018:
@ Asker Johannes is sadly duismissive of the importance of the term field (which he seems to have chosen to overlook in his own suggestion), but as i have insisted from the outset, the fact that this is leakage to ground from the FIELD circuit (primarily, the windings) is the whole crux of the issue here. In large generating systems, to avoid the use of such engineering horrors as slip-rings or commutators, it is standard practice for the field windings and excitation circuits to be fitted to the rotor, and the windings in which the wanted electricity is generated are more conveniently fitted to the stator, where there is more space available and the electricity can be tapped off more easily.
The unfortunate thing here is the use of the term 'field' at all, since clearly overall, a generator uses electromagnetic 'fields' to produce electricity; but more specifically, the term 'field' is used to refer to the 'excitation field' generated by the rotor, which takes the place of the permanent magnet 'field' used in an elementary generator when first invented.
Johannes Gleim May 20, 2018:
@ Catherine The full term is "FIELD GROUND DETECTOR" and not "FIELD GROUND". The main term is "GROUND DETECTOR", "FIELD" is only a noun modifier or specifier, referring to the transmission method of signals. As shown in the simplified one-line diagram the (closed-loop) control circuit contains two sections, where the signals are transmitted by electromagnetic induction, similar to a transformer, whose stationary part probably is the stator, while the rotating part is located on the shaft or the rotor. Unfortunately we do not have images of this arrangement. I conclude from this diagram, its description and your other question that the "GROUND DETECTOR" is located on the shaft as well and will detect and/or monitor any ground leakage. Hence I proposed the standard term "détecteur de fuite à la terre", even it may rotate with the shaft. Cf. your citation "rotating transmitter lights 8 LEDs when there is no field ground."
Johannes Gleim May 19, 2018:
@ Tony I do wonder why "field" should be identified with the rotor, as suggested. How can you confirm this? I cite your additional context:

"The EX2000BR excitation system controls the ac terminal voltage and/or the reactive volt amperes of the generator by controlling the excitation of the stationary exciter field."

An electromagnetic field is always excited by current flowing through wires and coils, i.e. the stator and rotor windings and is never a stator or rotor or any other material. This is base knowledge for each electrician or engineer.

An electromagnetic field (also EMF or EM field) is a physical field produced by electrically charged objects.[1] It affects the behavior of charged objects in the vicinity of the field.

See also:

The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction. It is one of the four fundamental forces of nature (the others are gravitation, weak interaction and strong interaction).
https://en.wikipedia.org/wiki/Electromagnetic_field
Tony M May 19, 2018:
@ Asker Thanks for that very helpful extra context, which generally confirms what I've been saying, albeit with additional complexity over and above the very simplified explanation I have been seeking to give here. There are detail differences, but the principle is the same: how to indicate ground leakage faults on a rotating element without any physical connection; the system described is a very elegant solution to this problem!
Catherine GEFFRAY (asker) May 19, 2018:
Introduction
The EX2000BR excitation system controls the ac
terminal voltage and/or the reactive volt amperes of
the generator by controlling the excitation of the
stationary exciter field. Referring to figure 1. The
EX2000BR contains a microprocessor regulator
(control core) and a power conversion module
(PCM). The conrol core regulates the ON/OFF time
of the transistors in the PCM. This produces a Pulse
Width Modulated (PWM) DC output which is fed
to the exciter field. The exciter field controls the
amount of AC voltage produced by the rotating
exciter armature. This AC voltage is converted to
DC by a rotating diode wheel. The DC power is
then fed to the generator field. Power for the
exciter field is drawn from the Power Potential
Transformer (PPT) which is fed from the motor
control center.
Catherine GEFFRAY (asker) May 19, 2018:
début de la phrase... The EX2000BR excitation system controls the ac
Johannes Gleim May 19, 2018:
@ Catherine Can you please disclose the type name of the device? "DIGITAL REGULATOR FOR BRUSHLESS EXCITATION SYSTEM" is not sufficient to determine kind and designation of the protecting devices. I have found a lot of different devices to monitor earth leakage currents and/or the insulation.
Catherine GEFFRAY (asker) May 19, 2018:
Bonjour Tony
Il s'agit de DIGITAL REGULATOR FOR BRUSHLESS
EXCITATION SYSTEM
Tony M May 19, 2018:
@ Asker What kind of equipment is this on, please? Makes all the differnece to the meaning of 'field'!

Proposed translations

8 hrs
English term (edited): field ground detector
Selected

détecteur de fuite à la terre (relais à détection de fuite à la terre)

The additional context shows that the device is a monitoring relay, which detects earth (ground) leakage currents. In order to enable clear distinction between this and other proposals I have to post it separately from my fist proposal.

EX2000BR Static Voltage Regulator for Brushless Excitation
The EX2000BR is a digital, static, voltage regulator for use with rotating ac brushless exciters. The system supplies dc excitation power to the field winding of the rotating brushless exciter. In addition, all control and protective functions are implemented in the system software. Digital technology allows the EX2000BR to maintain 99.98% availability.
A simplified one-line diagram of the EX2000BR excitation system is shown
below:
[diagram]
The voltage regulator accepts inputs from the generator terminals or auxiliary bus. In addition the regulator will accept a dc input from the station battery as a backup power source to the primary ac source.

This scheme looks like a closed-loop control. The only exception is that some signals are transmitted by electromagnetic fields, i.e. Motor and Generator, which may be mounted on the same shaft (not shown).
https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd...
(No mention of Field ground detector)

3.4.2 Generator Management Relay (G60)
:
· Neutral ground overvoltage (stator Earth Fault Protection) (64G)
:
6.2.7 Generator Excitation Systems, Static Components
· EX2000BR brushless field excitation regulator
http://www.generalequipment.info/FRAME7.htm

FIELD GROUND DETECTOR RELAY TYPE 64F STANDARD AND TEST CASE MANUAL – ABB
http://ecprentals.com/shop/field-ground-detector-relay-type-...
(This is a monitoring relay)

Le détecteur de fuite à la terre de champ détermine la résistance différentielle de sorte qu'elle puisse être contrôlée pour détecter une dégradation progressive de la résistance différentielle.
The field ground fault detector discerns the ground resistance so that it can be monitored to detect gradual degradation of the ground resistance.

Un détecteur de fuite à la terre différentiel est connecté électriquement à l'enroulement secondaire du transformateur de courant différentiel pour comparer le courant généré dans l'enroulement secondaire à partir d'un déséquilibre du flux magnétique dans le tore bobiné à un seuil de déclenchement.
A differential ground fault detector is electrically connected to the secondary winding of the differential current transformer to compare current generated in the secondary winding from an imbalance of magnetic flux in the toroid to a trip threshold.

Un détecteur de fuite à la terre surveille la tension aux deux bornes d'un premier élément résistant et la tension aux deux bornes d'un second élément résistant.
An earth leakage detector monitors the voltage at both ends of a first resistance element and the voltage at both ends of a second resistance element
http://context.reverso.net/traduction/francais-anglais/détec...

The field ground detector can differentiate between ground faults that occur on the AC side form those on the DC side of the Thyristor Bridge.
Le détecteur de fuite à la terre peut distinguer les fuites à la terre qui se produisent du côté courant alternatif de celles qui se produisent du côté courant continu du pont Thrystor.
https://glosbe.com/en/fr/field ground detector

Note: As the stator body is earthed/grounded, each fault current from the stator coil to the body will be detected due to the body grounding/earthing even the detector is only connected to the ground conductor (PE = protective earth). The correct term is therefore "détecteur de fuite à la terre".

--------------------------------------------------
Note added at 2 Tage 19 Min. (2018-05-21 10:05:03 GMT)
--------------------------------------------------

7.2.1 Rotor Design
… An illustration of the rotor is provided below.
(shows a rotor with coil slots and separated brushless exciter on the same shaft)
:
7.2.2 Stator Design
:
7.2.6 Switchgear Compartment
The switchgear compartment is a walk–in weather–protected enclosure made of carbon steel with a steel frame around the perimeter designed to support the enclosure
:
7.3.1 Packaged Electronic and Electrical Control Compartment (PEECC)
The PEECC is a completely enclosed compartment suitable for outdoor installation. … Electrical monitoring and control of the unit are accomplished by the turbine control panel and the generator control panel, which are mounted on a common skid and located in the PEECC.
:
7.3.2.6 Generator Interface and Control
The primary point of control for the generator is through the operator interface. However, the control system is integrated with the EX2000BR brushless excitation system over an Arcnet local area network (LAN). The SPEEDTRONIC Mark V is used to control megawatt output and the EX2000BR is used to control megavar output. The generator control panel is used to provide primary protection for the generator. This protection is further augmented by protection features located in the EX2000BR and the SPEEDTRONIC Mark V.
:
7.3.6 EX2000BR Static Voltage Regulator for Brushless Excitation
The EX2000BR is a digital, static, voltage regulator for use with rotating ac brushless exciters. …
(already cited)
https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd...
https://www.sec.gov/Archives/edgar/data/885568/0000950109015...

Machine Field Ground Detector Relay
3S7932YA122
The 3S7932YA122 machine field ground detector relay is a protection device used to detect abnormally low resistance between the field of a machine and ground. The panel incorporates a delay between the detection circuit and output contacts to prevent false indications when transient conditions exist. These transients are due to a current path through the shaft voltage suppression equipment which is necessary when there is a large ac component applied to the field.
https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd...



Area Rotating machinery / Winding arrangements
IEV ref 411-37-09
en field winding
an excitation winding contributing to the creation of the principal magnetic field of a machine
fr enroulement de champ, m
enroulement d'excitation contribuant à la création du champ magnétique principal d'une machine
http://www.electropedia.org/iev/iev.nsf/display?openform&iev...

Area Rotating machinery / Winding arrangements
IEV ref 411-37-08
en excitation winding
a winding for the production of a magnetic field which is stationary with respect to that winding
fr enroulement d'excitation, m
enroulement destiné à produire un champ magnétique qui est fixe par rapport à cet enroulement
http://www.electropedia.org/iev/iev.nsf/display?openform&iev...

Considering the new interpretation of "field" being the "field winding" I like to add "enroulement de champ" ou "enroulement d'excitation" to my proposal "détecteur de fuite à la terre (relais à détection de fuite à la terre)"
resulting in a term like "détecteur de fuite à la terre de l'enroulement de champ/d'exitation" or similaire.
Peer comment(s):
disagree Tony M : We don't know this is a relay of any kind, and ocne again, you too have missed out the all important 'field'; worse still, this 'field' is the ROTOR, not the stator! I'd also dispute 'terre' here, as this 'ground' is really more properly 'masse'.
55 mins
Thank you! I expected your focus on minor details like differences between earth and bodies. Please consider that rotor and stator have the same potential through the metallic bearings.
agree HERBET Abel : Oui bien sûr
3 hrs
Merci !
Something went wrong...
4 KudoZ points awarded for this answer. Comment: "Thanks"
+2
8 mins

(détecteur) de défaut d'isolement

une suggestion...
Note from asker:
Il s'agit de : DIGITAL REGULATOR FOR BRUSHLESS EXCITATION SYSTEM
Peer comment(s):
disagree Tony M : You have overlooked 'field' — in fact the crux of the matter here. So this suggestion would be incomplete, and hence in a technical translation, dangerously wrong. Non-technical people will not realize the significance of this, but it DOES matter.
2 hrs
j'ai l'habitude!!!!
agree writeaway : incomplete does not = wrong.
4 hrs
merci...
agree GILLES MEUNIER : c'est la meilleure réponse
6 hrs
merci
agree Kim Metzger
8 hrs
merci
neutral Johannes Gleim : Pas "d'isolement", mais "fuite à la terre".
8 hrs
Something went wrong...
+1
3 hrs
English term (edited): field ground (detector)

(dispositif de détection) de fuites à la masse de la bobine d'excitation

This is referring to a system for detecting ground leakage from the field winding (i.e. rotor winding) in a generator. As such, it is vital to keep 'field' in the translation. Though note that it is more often described as 'inducteur/trice' or 'excitation' in FR.

So the field windings are on the rotor that is spinning at high speed, with no (intentional!) connection to the outside world; thus the spinning LED array is illuminated in the absence of a ground leakage fault (as Florence rightly says, due to a 'défault d'isolement'); the exciter unit must include some circuit to detect any such leakage and extinguish the relevant LED. Thus light is used to convey the fault information, hence no physical connection is needed.

The EN is highly telegraphic, which is what makes it awkward to interpret; I have suggested a much more long-winded "explanation" in FR, as I felt it was important to start by interpreting the EN source text properly.

I'll leave it to our FR native-speaker colleagues to suggest ways to re-word this more succinctly!

--------------------------------------------------
Note added at 3 hrs (2018-05-19 13:37:13 GMT)
--------------------------------------------------

Note also that 'ground here is not (necessarily) the same as 'earth', hence why I have specifically suggested 'masse', which in essences is the local machine ground — but might not be actually connected to Earth earth (though one would usually hope it would be!)

At this level of detail, 'earth' and 'ground' are not simply interchangeable terms, as we often regard them as being (BE vs. AE).
Peer comment(s):
agree Kim Metzger
1 hr
Thanks, Kim! ;-)
Something went wrong...
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