Hitachi RED670 - Current Reversal Logic; Weak End Infeed Logic

11.11.3.2 Current reversal logic
M14947-8 v3
It is possible to check the delay of the CS send signal with tDelayRev by changing from a reverse to
a forward fault.
By continuously activating the CR input and changing from a reverse to a forward fault, the delay
tDelayRev can be checked.
Checking of current reversal
M14947-13 v9
The reverse zone timer must not operate before the forward zone fault is applied.
The user might need to block the reverse zone timer setting during testing of current
reversal.
The forward zone timer must be set longer than the tDelayRev set value.
1. Set the healthy condition to an impedance at 50% of the reach of the reverse zone connected
to IRV.
2. Activate the receive (CRL) signal.
3. After the start condition is obtained for reverse zone, apply a fault at 50% of the reach of the
forward zone connected to WEIBLK2.
4. Check that correct trip outputs and external signals are obtained for the type of fault generated.
The operation time should be about the tDelayRev setting longer than the carrier accelerated
trip (TRIP) recorded for the permissive overreach scheme communication.
5. Restore the forward and reverse zone timer to its original setting.
11.11.3.3 Weak end infeed logic
M14947-37 v2
Weak-end infeed logic at permissive overreach schemes
M14947-39 v5
1. Check the blocking of the echo with the injection of a CRL signal >40ms after a reverse fault is
applied.
2. Measure the duration of the echoed CS signal by applying a CRL receive signal.
3. Check the trip functions and the voltage level for trip by reducing a phase voltage and applying
a CRL receive signal.
Testing conditions
M14947-52 v7
Only one type of fault is sufficient, with the current reversal and weak-end infeed logic for distance
protection function ZCRWPSCH. Apply three faults (one in each phase). For phase L1-N fault, set
these parameters:
Table 41: Phase L1-N parameter values
Phase
I (Amps) Phase-angle
(Deg)
V (Volts) Phase-angle
(Deg)
L1 0 0 Set less than UPN< 0
L2 0 240 63 240
L3 0 120 63 120
If wanted, change all settings cyclically for other faults (L2-N and L3-N).
Section 11 1MRK 505 378-UEN Rev. K
Testing functionality by secondary injection
222 Line differential protection RED670
Commissioning manual
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