ABB Relion 670 Series Applications Manual page 368

Section 13
Control
VRAISE/VLOWER
tTCTimeout
TCINPROG
ANSI06000482 V1 EN-US
Figure 174: Timing of pulses for tap changer operation monitoring
pos Description
a Safety margin to avoid that TCINPROG is not set high without the simultaneous presence of an VRAISE or
VLOWER command.
b Time setting
c Fixed extension 4 sec. of
d Time setting
e New tap position reached, making the signal "tap change in progress" disappear from the tap changer, and a
new position reported.
f The new tap position available in TCMYLTC (84) or TCLYLTC (84).
g Fixed extension 2 sec. of TCINPROG, made internally in TCMYLTC (84) or TCLYLTC (84) function.
h Safety margin to avoid that TCINPROG extends beyond
The first use is to reset the Automatic voltage control for tap changer function TR1ATCC (90) for
single control and TR8ATCC (90) for parallel control as soon as the signal TCINPROG disappears. If
the TCINPROG signal is not fed back from the tap changer mechanism, TR1ATCC (90) or TR8ATCC
(90) will not reset until
signal in this case is thus that resetting of TR1ATCC (90) or TR8ATCC (90) can sometimes be made
faster, which in turn makes the system ready for consecutive commands in a shorter time.
The second use is to detect a jammed tap changer. If the timer
TCINPROG signal is set back to zero, the output signal TCERRAL is set high and TR1ATCC (90) or
TR8ATCC (90) function is blocked.
The third use is to check the proper operation of the tap changer mechanism. As soon as the input
signal TCINPROG is set back to zero TCMYLTC (84) or TCLYLTC (84) function expects to read a
new and correct value for the tap position. If this does not happen the output signal CMDERRAL is
set high and TR1ATCC (90) or TR8ATCC (90) function is blocked. The fixed extension (g) 2 sec. of
TCINPROG, is made to prevent a situation where this could happen despite no real malfunction.
In figure 174, it can be noted that the fixed extension (c) 4 sec. of
situation with TCINPROG set high without the simultaneous presence of an VRAISE or VLOWER
command. If this would happen, TCMYLTC (84) or TCLYLTC (84) would see this as a spontaneous
TCINPROG signal without an accompanying VRAISE or VLOWER command, and this would then
362
b c
a
tPulseDur .
tPulseDur , made internally in TCMYLTC (84) or TCLYLTC (84) function.
tStable
tTCTimeout has timed out. The advantage with monitoring the TCINPROG
g
e f
h
d
en06000482_ansi.vsd
tTCTimeout .
tTCTimeout times out before the
tPulseDur , is made to prevent a
1MRK 511 358-UUS A
Application manual