Second Harmonic Blocking Element - ABB RET650 Technical Manual

Section 8
Current protection
0.6
X
I>Dir
X
0.4
polMethod=Voltage
polMethod=Dual
polMethod=Current
RNPol
XNPol
BLOCK
IEC07000067 V5 EN
Figure 74: Simplified logic diagram for directional supervision element with integrated directional comparison
step
8.4.8
170
These signals shall be used for communication based earth-fault teleprotection
communication schemes (permissive or blocking).
Simplified logic diagram for directional supervision element with integrated
directional comparison step is shown in figure 74:
| IopDir |
a
a>b
b
a
a>b
b
OR
UPol
OR
IPol
T
0.0
F
X
Complex
Number

Second harmonic blocking element

A harmonic restrain of the Four step residual overcurrent protection function
EF4PTOC can be chosen. If the ratio of the 2nd harmonic component in relation to the
fundamental frequency component in the residual current exceeds the pre-set level
defined by parameter setting 2ndHarmStab. Any of the four residual overcurrent
stages can be selectively blocked by parameter setting HarmRestrainx. When 2nd
harmonic restraint feature is active the EF4PTOC function output signal
2NDHARMD will be set to logical value one.
AND
REVERSE_Int
AND
FORWARD_Int
AngleRCA
UPolMin
IPolMin
T
I3PDIR
0.0
F
UTotPol
UIPol
STAGE1_DIR_Int
T
STAGE2_DIR_Int
0.0
F
STAGE3_DIR_Int
STAGE4_DIR_Int
1MRK 504 135-UEN A
STRV
STFW
FWD
AND FORWARD_Int
AND
REVERSE_Int
RVS
OR
AND
IEC07000067-5-en.vsd
Technical manual