ABB Relion 670 series - Page 412

7.13.8.4 Simplified logic diagram
GUID-F92413ED-371C-4962-AF72-7BF8D5A188C2 v1
V
Rshunt
ROTIPHIZ (64R)
REX060
REG670
1
I
V
v_i_ref
v_v_ref
X
S
K1
K2
Compare &
Evaluate
ZRef1
ZRef2
3
2
4
56
7
ANSI10000327_1_en.vsd
bare
Z
Measured
Z
Inj
I
Inj
V
¸
R
f
inj
ANSI10000327 V1 EN-US
Figure 218: Simplified logic diagram for sensitive rotor earth fault protection, injection based
ROTIPHIZ (64R)
1 The sensitive rotor earth fault protection function receives amplified injected voltage and current via
the REX060 unit as two voltages signals. (Voltage inputs in the IED)
2 The phasor of injected voltage V
Inj
and phasor of injected current I
Inj
is calculated by using special filter
from raw samples. Observe that phasors are calculated for the injected frequency.
3 The complex bare impedance is calculated from V
inj
/ I
inj
.
4, 5 The complex measured impedance is derived as Z
Measured
= Z
bare
* k1 + k2 [Ω].
6 The fault resistance (R
f
) is calculated from the complex measured impedance and a selected complex
reference.
7 Selection of one (out of maximum 2) Z
Ref
.
Section 7 1MRK 502 066-UUS B
Impedance protection
406
Technical manual