Micom P634 - Amplitude Matching

Q6Z0102B
Parameter
set 1
set 2
set 3
set 4
DIFF:
Enable PSx
072 152
073 152
074 152
075 152
DIFF:
Enabled
[ 041 210 ]
DIFF:
Enable PSx
[ * ]
1
0
0: No
1: Yes
0
0: No
1: Yes
DIFF:
General enable USER
[ 019 080 ]
1
DIFF:
Blocking EXT
[ 003 163 ]
DIFF:
Ready
303 299
Fig. 3-85: Enabling or disabling differential protection
3.21.2 Amplitude Matching
In order to set the amplitude matching for the protected object, a reference
power - identical for all windings - needs to be defined. For two-winding
arrangements, the nominal power will usually be the reference power. For three-
or four-winding transformers, the nominal power of the highest-power winding
should be set as the reference power. The individual reference currents for each
winding of the protected object are then calculated by the P634 on the basis of
the set reference power and the set primary nominal voltages of the transformer.
I
ref ,a
=
S
ref
3 ⋅ V
nom,a
I
ref ,b
=
S
ref
3 ⋅ V
nom,b
I
ref ,c
=
S
ref
3 ⋅ V
nom,c
I
ref ,d
=
S
ref
3 ⋅ V
nom,d
with
S
ref
: reference power
I
ref ,a...d
: reference current of winding a, b, c or d
V
nom,a...d
: nominal voltage of winding a, b, c or d
The P634 calculates the matching factors on the basis of the reference currents
and the set primary nominal currents of the system transformers.
k
am,a
=
I
nom,a
I
ref ,a
P634
3 Operation
3-124 P634/EN M/R-42-A // P634‑311‑653