ABB REC670 Applications Manual page 387

1MRK 511 401-UEN A
Bay control REC670 2.2 IEC
Application manual
operation during shorter voltage deviations from the target value, and in order to
coordinate with other automatic voltage controllers in the system.
TCMYLTC and TCLYLTC are an interface between the Automatic voltage control
for tap changer, TR1ATCC or TR8ATCC and the transformer load tap changer
itself. More specifically this means that it gives command-pulses to a power
transformer motor driven load tap changer and that it receives information from the
load tap changer regarding tap position, progress of given commands, and so on.
TCMYLTC and TCLYLTC also serve the purpose of giving information about tap
position to the transformer differential protection.
Control location local/remote
The tap changer can be operated from the front of the IED or from a remote place
alternatively. On the IED front there is a local remote switch that can be used to
select the operator place. For this functionality the Apparatus control function
blocks Bay control (QCBAY), Local remote (LOCREM) and Local remote control
(LOCREMCTRL) are used.
Information about the control location is given to TR1ATCC or TR8ATCC
function through connection of the Permitted Source to Operate (PSTO) output of
the QCBAY function block to the input PSTO of the TR1ATCC or TR8ATCC
function block.
Control Mode
The control mode of the automatic voltage control for tap changer function,
TR1ATCC for single control and TR8ATCC for parallel control can be:
• Manual
• Automatic
The control mode can be changed from the local location via the command menu
on the local HMI under Main menu/Control/Commands/
TransformerVoltageControl(ATCC,90)/TR1ATCC:x/TR8ATCC:x, or changed
from a remote location via binary signals connected to the MANCTRL,
AUTOCTRL inputs on TR1ATCC or TR8ATCC function block.
Measured Quantities
In normal applications, the LV side of the transformer is used as the voltage
measuring point. If necessary, the LV side current is used as load current to
calculate the line-voltage drop to the regulation point.
Automatic voltage control for tap changer, TR1ATCC for single control and
TR8ATCC for parallel control function block has three inputs I3P1, I3P2 and U3P2
corresponding to HV-current, LV-current and LV-voltage respectively. These
analog quantities are fed to the IED via the transformer input module, the Analog
to Digital Converter and thereafter a Pre-Processing Block. In the Pre-Processing
Block, a great number of quantities for example, phase-to-phase analog values,
sequence values, max value in a three phase group etc., are derived. The different
Section 14
Control
SEMOD159053-30 v3
SEMOD159053-35 v4
SEMOD159053-61 v4
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