ABB REG670 Applications Manual page 579

1MRK 502 071-UEN -
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
Setting Values (Range)
TapPosBk Alarm
(automatically Auto Block
reset/manually Auto&Man Block
reset)
CircCurrBk Alarm
(automatically Auto Block
reset) Auto&Man Block
MFPosDiffBk Alarm
(manually reset) Auto Block
Setting parameters for blocking that can be set in TR1ATCC or TR8ATCC under
setting group Nx in PST/ local HMI are listed in table 60.
Description
This blocking/alarm is activated by either:
1. The tap changer reaching an end position i.e. one of
the extreme positions according to the setting
parameters LowVoltTap and HighVoltTap . When the
tap changer reaches one of these two positions
further commands in the corresponding direction will
be blocked. Effectively this will then be a partial block
Auto Block or Auto&Man Block is set. The outputs
if
POSERRAL and LOPOSAL or HIPOSAL will be
activated.
2. Tap Position Error which in turn can be caused by one
of the following conditions:
• Tap position is out of range that is, the indicated
position is above or below the end positions.
• The tap changer indicates that it has changed more
than one position on a single raise or lower command.
• The tap position reading shows a BCD code error
(unaccepted combination) or a parity fault.
• The reading of tap position shows a mA value that is
out of the mA-range. Supervision of the input signal
for MIM is made by setting the MIM parameters I_Max
and I_Min to desired values, for example, I_Max =
20mA and I_Min = 4mA.
• Very low or negative mA-values.
• Indication of hardware fault on BIM or MIM module.
Supervision of the input hardware module is provided
by connecting the corresponding error signal to the
INERR input (input module error) or BIERR on
TCMYLTC or TCLYLTC function block.
• Interruption of communication with the tap changer.
The outputs POSERRAL and AUTOBLK or TOTBLK will be
set.
This error condition can be reset by the input RESETERR
on TCMYLTCfunction block, or alternatively by changing
control mode of TR1ATCC or TR8ATCC function to Manual
and then back to Automatic.
When the magnitude of the circulating current exceeds the
preset value (setting parameter
time than the set time delay (setting parameter
will cause this blocking condition to be fulfilled provided that
the setting parameter OperCCBlock is On . The signal
resets automatically when the circulating current decreases
below the preset value. Usually this can be achieved by
manual control of the tap changers. TR1ATCC or
TR8ATCC outputs ICIRC and TOTBLK or AUTOBLK will be
activated depending on the actual parameter setting.
In the master-follower mode, if the tap difference between a
follower and the master is greater than the set value (setting
MFPosDiffLim ) then this blocking condition is
parameter
fulfilled and the outputs OUTOFPOS and AUTOBLK
(alternatively an alarm) will be set.
Section 15
Control
CircCurrLimit ) for longer
tCircCurr ) it
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