Technical Data - ABB Relion Technical Manual

1MRK 502 048-UUS A
6.1.4
Technical manual
sequence differential protection TRNSSENS and common trip TRIP are issued. This
feature is called the sensitive negative sequence differential protection.
5. If a pickup signal is issued in a phase (see signal PU_A), even if the fault has been
classified as an external fault, then the instantaneous differential current of that phase
(see signal ID_A) is analyzed for the 2
with the text inside: 2nd Harmonic; Wave block and 5th Harmonic). If there is less
harmonic pollution, than allowed by the settings I2/I1Ratio, and I5/I1Ratio, (then the
outputs from the blocks 2nd harmonic and 5th harmonic is 0) then it is assumed that
a minor simultaneous internal fault must have occurred. Only under these conditions
a trip command is allowed (the signal TRIPRES_A is = 1). The cross-block logic
scheme is automatically applied under such circumstances. (This means that the cross
block signals from the other two phases B and C is not activated to obtain a trip on the
TRIPRES_A output signal in figure 38)
6. All pickup and blocking conditions are available as phase segregated as well as
common signals.
IDMAG_A Diff
IDiffAlarm
IDMAG_B Diff
IDiffAlarm
IDMAG_C Diff
IDiffAlarm
ANSI06000546 V2 EN
Figure 42: Differential current alarm logic

Technical data

Table 30: T2WPDIF, T3WPDIF (87T) technical data
Function
Operating characteristic
Reset ratio
Unrestrained differential current limit
Table continues on next page
nd
and the 5
a
a>b
b
a
a>b
b
a
a>b
b
Range or value
Adaptable
>94%
(1.00-50.00)x
high voltage winding
Differential protection
th
harmonic contents (see the blocks
0-tAlarmDelay
&
0
ANSI06000546-2-en.vsd
Accuracy
± 1.0% of In for I < In
± 1.0% of I for I > In
-
IBase on ± 1.0% of set value
Section 6
IDALARM
117