ABB Relion 670 series - Second harmonic blocking element

X
a
a>b
b
IDirPU
polMethod=Voltage
polMethod=Dual
OR
FORWARD_Int
REVERSE_Int
BLOCK
STAGE1_DIR_Int
0.6
X
0.4
AND
STAGE3_DIR_Int
STAGE4_DIR_Int
STAGE2_DIR_Int
OR
PUREV
VPolMin
IPolMin
AngleRCA
T
F
0.0
X
T
F
RNPol
XNPol
0.0
D
i
r
e
c
t
i
o
n
a
l
C
h
a
r
a
c
t
e
r
i
s
t
i
c
FWD
RVS
AND
AND
AND
PUFW
FORWARD_Int
REVERSE_Int
AND
ANSI07000067-4-en.vsd
|
|
VPol
VIPol
I3PDIR
VTPol
IopDir
Complex
Number
a
a>b
b
IPol
T
F
0.0
polMethod=Current
OR
ANSI07000067 V4 EN
Figure 208: Simplified logic diagram for directional supervision element with integrated directional comparison step
7.4.2.8 Second harmonic blocking element
A harmonic restrain of four step residual overcurrent protection function EF4PTOC
can be chosen for each step by a parameter setting HarmRestrainx. If the ratio of the
2nd harmonic component in relation to the fundamental frequency component in the
residual current exceeds the preset level (defined by parameter 2ndHarmStab) then
2NDHARMD function output signal is set to logical value one and harmonic
restraining feature to the function block will be applicable.
Blocking from 2nd harmonic element activates if all three criteria are satisfied:
Section 7 1MRK505222-UUS C
Current protection
408
Technical reference manual