ABB Relion 670 Series Applications Manual page 494

Section 17
Monitoring
Setting
AgeingRateMeth
ThermalUpgrade
TimeToUpdate
WrnHPTmpLev1
WrnHPTmpLev2
tDelayToAlarm1
tDelayToAlarm2
17.12 Through fault monitoring PTRSTHR (51TF)
17.12.1 Identification
Function description
Through fault monitoring
17.12.2 Application
The through fault monitoring function PTRSTHR(51TF) is used to monitor the mechanical stress on
a transformer and place it against its withstand capability. During through faults, the fault-current
magnitude is higher as the allowed overload current range. At low fault current magnitudes which
are below the overload capability of the transformer, mechanical effects are considered less
important unless the frequency of fault occurrence is high. Since through fault current magnitudes
are typically closer to the extreme design capabilities of the transformer, mechanical effects are
more significant than thermal effects.
The point of transition between mechanical stress and thermal stress cannot be precisely defined.
However, mechanical stresses tend to have a prominent role in larger kilovolt-amps ratings, since
the currents are higher. It is important to identify all transformer through faults, capture the
energy profile of each individual through fault, and ascertain the consequences of aggregate
effects to the transformer.
According to IEEE C57.12.00-1993 standard, transformers rated over 10 MVA come under category
IV. For these transformers, a single curve represents both thermal and mechanical damage
considerations. The recommended duration limit is based upon the curve in
validity of these damage limit curves cannot be demonstrated by tests since the effects are
cumulative over the transformers lifetime. They are based principally on informed engineering
judgment and favorable, historical field experience as said in IEEE standard.
488
Short Description
Select the ageing rate method of
calculation
Select the transformer insulation
paper type
Set the time interval for the update of
loss of life outputs
Set the hot spot temperature value for
the level 1 warning
Set the hot spot temperature value for
the level 2 warning
Set the time delay for the alarm level 1
Set the time delay for the alarm level 2
IEC 61850
identification
PTRSTHR
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Selected value
IEC
Upgraded
1 Hour
110° C
120° C
1800 sec
900 sec
IEC 60617 ANSI/IEEE C37.2
identification device number
- 51TF
1MRK 511 401-UUS F
GUID-7AE60CB5-3CD5-4FE2-8D54-664AA78DD2DE v1
GUID-B62A30E5-C1F3-4E1F-B351-4F4CC60BA53F v1
GUID-A859F4D6-635E-4116-9416-EF50948FA6C9 v1
Figure 222. The
Bay control REC670
Application manual