ABB Remote I/O RIO600 Installation And Commissioning Manual page 161

1MRS757488 H
RIO600
Installation and Commissioning Manual
earth-fault ignition moment. Therefore, setting Revert Time should
have sufficient big value, at least 300 ms.
Faulted phase selection
The Faulted phase selection module provides information about the faulted phase (A,
B or C) during a single-phase earth fault.
The faulted phase is identified by evaluation of the following equations:
FAULTED PHASE A =
abs
GUID-2F1B1452-1228-4938-B1A4-3FD5AB349F8C V1 EN
FAULTED PHASE B =
GUID-4A1CC3EC-B50A-4D97-9A71-C7F353D6F18C V1 EN
FAULTED PHASE C =
GUID-7155A708-DFC6-4A61-B643-D341DA65442D V1 EN
where
ΔI = I (t ) - I (t
A A FLT A PRE_FLT
ΔI = I (t ) – I (t
B B FLT B PRE_FLT
ΔI = I (t ) – I (t
C C FLT C PRE_FLT
Faulted phase is identified by comparing the magnitudes of
Equation 20 has a minimum value, the faulted phase is A. If
minimum value, the faulted phase is B. If
faulted phase is C.
Actual implementation uses Cumulative Phasor Summing (CPS) calculation. This
filtering method is especially advantageous during transient, intermittent and re-
striking earth faults with dominantly non-sinusoidal or transient content. But it is
equally valid during continuous (stable) earth faults. The concept of CPS is illustrated
in the figure below.
 
 
∆ 1 − ∆ 1
 I I 
B C
( )
 
1 1
∆ + ∆
I I
 
B C
1
∆ −
  
I
 A 
2
 
 
1 1
∆ − ∆
 I I 
C A
abs
( )
 
∆ 1 + ∆ 1
I I
 
C A
∆ 1 −
 I  
 B 
2
 
 
1 1
∆ − ∆
I I
 
A B
abs
( )
 
∆ 1 + ∆ 1
I I
 
A B
∆ 1 −
  
I
C
 
2
) = change of phase A current phasor due to earth fault
) = change of phase B current phasor due to earth fault
) = change of phase C current phasor due to earth fault
Equation 22
Section 6
Commissioning
(Equation 20)
(Equation 21)
(Equation 22)
Equations 20 - 22. If
Equation 21 has a
has a minimum value, the
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