ABB Relion 650 Series Technical Manual page 485

1MRK 506 326-UUS B
If the imaginary part of K
to equation 94. According to equation 94, the relative distance to the fault is solved as the root of
a quadratic equation.
Equation
simplified load compensated algorithm, which gives an unequivocal figure for the relative distance
to the fault, is used to establish the value that should be selected.
If the load compensated algorithms according to the above do not give a reliable solution, a less
accurate, non-compensated impedance model is used to calculate the relative distance to the
fault.
13.13.7.3 The non-compensated impedance model
In the non-compensated impedance model, I
= ×
V p Z
A
EQUATION1603 V1 EN-US
Where:
I
A
The accuracy of the distance-to-fault calculation, using the non-compensated impedance model, is
influenced by the pre-fault load current. So, this method is only used if the load compensated
models do not function.
13.13.8 Technical data
Table 421: LMBRFLO technical data
Function
Reactive and resistive reach
Phase selection
Maximum number of fault
locations
Line distance protection REL650
Technical manual
is not zero, R
3
94 gives two different values for the relative distance to the fault as a solution. A
× + ×
I R I
1L A F A
is according to table 420.
Value or range
(0.001-1500.000) Ω/phase
According to input signals
100
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can be solved according to equation 95, and then inserted
F
line current is used instead of I
A
Accuracy
± 2.0% static accuracy
± 2.0% degrees static angular accuracy
Conditions:
Voltage range: (0.1-1.1) x V
Current range: (0.5-30) x I
-
-
Section 13
Monitoring
M14983-121 v3
fault current:
FA
(Equation 96)
IP14084-1 v1
M14987-1 v4
n
n
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