ABB RELION 670 Series Technical Manual page 520

Section 8
Current protection
The inverse time delay is defined as:
TDSN
t
=
inv
EQUATION2032-ANSI V2 EN-US
Directional residual current protection measuring 3I
The function will operate if the residual current is larger than the set value and the angle |φ =
ang(3I )-ang(V
0
ANSI06000652 V2 EN-US
Figure 270: Example of characteristic
For trip, Residual current 3I
3V shall be larger than the
0
ROADir and RCADir . Refer to the simplified logical diagram in Figure 271.
Trip from this function can be blocked from the binary input BLKTRDIR.
When the function picks up, binary output signals PICKUP and PUDIRIN are activated. If the output
signals PICKUP and PUDIRIN remain active for the set delay
and TRDIRIN get activated.
The function indicates forward/reverse direction to the fault. Reverse direction is defined as φ is
within the angle sector:
This variant has definite time delay.
Directional functions
For all the directional functions there are directional pickup signals PUFW: fault in the forward
direction, and PUREV: fault in the reverse direction. Even if the directional function is set to
operate for faults in the forward direction, a fault in the reverse direction will give the pickup
514
ϕ
( 3 3 cos (
I V reference
⋅ ⋅ ⋅
0 0
ϕ
3 3 cos ( )
I V measured
⋅ ⋅
0 0
)| is within the sector
ref
RCA = 0º
ROA = 80º
shall be larger than both
0
VNRelPU . In addition, the angle φ shall be in the set area defined by
RCADir + 180° ± ROADir
))
and φ
0
RCADir ± ROADir
Operate area
3I
0
V =-3V
ref 0
ANSI06000652-2-en.vsd
INRelPU and INDirPU , and residual voltage
tDef the binary output signals TRIP
1MRK 502 066-UUS B
(Equation 133)
SEMOD171963-48 v4
SEMOD171963-60 v4
Technical manual