Simplified Logic Diagrams; Technical Data - ABB RET650 Technical Manual

Section 7
Impedance protection
7.3.6.2
7.3.7
140

Simplified logic diagrams

Figure 61 schematically presents the creation of the phase-to-phase operating
conditions.
X
L1
R
L1L2
I ³
3 0.05
0
&
³ ×
3 I 0.2 I
0 phmax
BLOCK
I <
3 0.1
0
OR
< ×
3 I 0.4 I
0 phmax
IEC10000226 V1 EN
Figure 61: Phase-to-phase L1L2 operating conditions (residual current criteria)
Special attention is paid to correct phase selection at evolving faults. A STCNDLE
output signal is created as a combination of the load encroachment characteristic and
current criteria, refer to figure 61. This signal can be configured to STCND functional
input signals of the distance protection zone and this way influence the operation of
the phase-to-phase zone measuring elements and their phase related starting and
tripping signals.

Technical data

Table 65: LEPDIS technical data
Function
Load encroachment criteria:
Load resistance, forward and
reverse
Safety load impedance angle
Reset ratio
&
&
&
20 ms
10 ms
t
&
t
Range or value
(1.00–3000.00) Ω/phase
(5-85) degrees
105% typically
1MRK 504 135-UEN A
Block
STCNDLE
Bool to &
integer
IEC10000226-1-en.vsd
Accuracy
± 5.0% static accuracy
± 2.0 degrees static angular
accuracy
Conditions:
Voltage range: (0.1-1.1) x U
Current range: (0.5-30) x I
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Technical manual
r
r