ABB Relion 650 Series Technical Manual page 142

Section 5
Impedance protection
on one line and a C fault on another line. For
(C before A) while for
Table 46: Operation modes for Phase preference logic
OperMode
No filter
No pref
1231 c
1321 c
123 a
132 a
213 a
231 a
312 a
321 a
The function can be divided into two parts; one labeled voltage and current discrimination and the
second one labeled phase preference evaluation, see figure 77.
The aim with the voltage and current discrimination part is to discriminate faulty phases and to
determine if there is a cross-country fault. If cross-country fault is detected, an internal signal
"Detected cross-country fault" is created and sent to the phase preference part to be used in the
evaluation process for determining the condition for trip.
The voltage and current discrimination part gives phase segregated pickup signals if the
respective measured phase voltage is below the setting parameter
the zero sequence voltage is above the setting parameter
phase the PICKUP output signal will be activated.
The internal signal for detection of cross-country fault, DetectCrossCountry, that come from the
voltage and current discrimination part of the function can be achieved in three different ways:
1. The magnitude of 3I
the setting of pick-up timer
2. The magnitude of 3I
magnitude of 3V
the setting of pick-up timer
3. The magnitude of 3I
of the following conditions are fulfilled:
•
•
The second part, phase preference evaluation, uses the internal signal DetectCrossCountry from
the voltage and current evaluation together with the input signal PHSEL together with phase
136
OperMode = 123a the line with A 1 fault will be tripped (A before C).
Description
No filter, phase-to-phase measuring loops are not blocked during single
phase-to-ground faults. Tripping is allowed without any particular phase
preference at cross-country faults
No preference, trip is blocked during single phase-to-ground faults, trip is
allowed without any particular phase preference at cross-country fault
Cyclic 1231c; A before B before C before C
Cyclic 1321c; A before C before B before A
Acyclic 123a; A before B beforeC
Acyclic 132a;A before C beforeB
Acyclic 213a; B before A before C
Acyclic 231a; B before C beforeA
Acyclic 312a; C before B beforeA
Acyclic 321a; C before B before A
has been above the setting parameter
0
tIN .
has been above the setting parameter
0
has been above the setting parameter
0
tVN .
has been above the setting parameter
0
the measured phase-to-phase voltage in at least one of the phase combinations has
been below the setting parameter
At least two of the phase voltages are below the setting parameter
than 20 ms.
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OperMode = 1231c the line with C fault will be tripped
PU27PN at the same time as
3V0Pickup . If there is a pickup in any
Pickup_N for a time longer than
Pickup_N at the same time as the
3V0Pickup during a time longer than
Pickup_N at the same time as one
PU27PP for more than 20 ms.
1MRK 506 326-UUS B
PU27PN for more
Line distance protection REL650
Technical manual