ABB Relion 670 Series Technical Reference Manual page 411

1MRK505222-UUS C
7.4.2.7
Technical reference manual
• Time delay related settings. By these parameter settings the properties like definite
time delay, minimum operating time for inverse curves, reset time delay and
parameters to define user programmable inverse curve are defined.
• Supervision by second harmonic blocking feature (Enabled/Disabled). By this
parameter setting it is possible to prevent operation of the step if the second
harmonic content in the residual current exceeds the preset level.
• Multiplier for scaling of the set residual current pickup value by external binary
signal. By this parameter setting it is possible to increase residual current pickup
value when function binary input MULTPUx has logical value 1.
Simplified logic diagram for one residual overcurrent step is shown in figure 206.
BLKTR
IMinx
X
T
F
|I |
OP
MultPUx
X
T
F
Pickupx
BLKx
BLOCK
2ndHarm_BLOCK_Int
HarmRestrainx=Disabled
DirModex=Off
DirModex=Non-directional
DirModex=Forward
DirModex=Reverse
ANSI10000008 V1 EN
Figure 206: Simplified logic diagram for residual overcurrent step x, where x = step
1, 2, 3 or 4
The protection can be completely blocked from the binary input BLOCK. Output
signals for respective step, and PUSTx and TRSTx, can be blocked from the binary
input BLKx. The trip signals from the function can be blocked from the binary input
BLKTR.
Directional supervision element with integrated directional comparison
function
It shall be noted that at least one of the four residual overcurrent steps
shall be set as directional in order to enable execution of the directional
supervision element and the integrated directional comparison function.
Characteristx=DefTime
b
a>b
a
a
a>b
b
AND
AND
Characteristx=Inverse
OR
OR STEPx_DIR_Int
AND
OR
FORWARD_Int
AND
REVERSE_Int
Section 7
Current protection
tx
OR
tMin
Inverse
TRSTx
AND
PUSTx
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