Micom P634 - Tripping Characteristics

MAIN:
Phase sequence
[ 010 049 ]
64Z6011A
Parameter
set 1
set 2
set 3
set 4
DIFF:
Vec.gr. ends a-d PSx
019 014
019 046
019 047
019 048
DIFF:
0-seq. filt.d en.PSx
072 154
073 154
074 154
075 154
DIFF:
Vec.gr. ends a-d PSx
[ * ]
Iam,0,d
Iam,A,d
Iam,B,d
Iam,C,d
Is,1,d
Is,2,d
Is,3,d
Is,y,d
DIFF:
0-seq. filt.d en.PSx
[ * ]
0: No
1: Yes
0
2
4
6
8
10
12
1
3
5
7
9
11
0
1
Fig. 3-90: Vector group matching and zero-sequence filtering, end d
3.21.5 Tripping Characteristics
The differential and restraining current values for each measurement system are
calculated from the current values after amplitude and vector group matching.
The formation of the restraining values differs between two- and three-winding
protection The following equations are valid for uniformly defined current arrows
relative to the protected equipment, e.g. all the current arrows of all windings
point either towards the protected object or away from it.
Calculation of differential and restraining currents:
I
d,y
=
|
I
s,y,a
+ I
s,y,b
+ I
s,y,c
+ I
s,y,d
|
I
R,y
= 0.5 ⋅
| |
I
s,y,a
|
+
|
I
s,y,b
|
+
|
I
s,y,c
|
+
|
I
s,y,d
| |
The tripping characteristic of the P634 line differential protection device has two
knee points. The first knee-point depends on the setting at DIFF: Idiff> PSx
and is on the intersection with the tripping characteristic for single-side feed.
If the current transformer supervision (CTS) function is used, the basic pick-up
sensitivity DIFF: Idiff> PSx can be increased to a set value
(DIFF: Idiff>(CTS) PSx) when a CT fault is detected. See details given in the
section describing the CTS function group.
The second knee of the tripping characteristic is defined by the setting at
DIFF: Idiff> PSx.
The characteristic equations for the three different ranges are given below.
Fig. 3-91, (p. 3-133) shows the tripping characteristic.
Characteristics equation for the range 0 ≤ I
R
≤ 0.5I
diff >
:
P634
3 Operation
3-132 P634/EN M/R-42-A // P634‑311‑653