ABB Relion 670 Series Applications Manual page 341

1MRK 511 358-UUS A
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 (90) or TR8ATCC (90) function through
connection of the Permitted Source to Operate (PSTO) output of the QCBAY function block to the
input PSTO of the TR1ATCC (90) or TR8ATCC (90) function block.
Control Mode
The control mode of the automatic voltage control for tap changer function, TR1ATCC (90) for
single control and TR8ATCC (90) 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 (90) or TR8ATCC (90) 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 (90) for single control and TR8ATCC (90) for
parallel control function block has three inputs I3P1, I3P2 and V3P2 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 function
blocks in the IED are then "subscribing" on selected quantities from the pre-processing blocks. In
case of TR1ATCC (90) or TR8ATCC (90), there are the following possibilities:
• I3P1 represents a three-phase group of phase current with the highest current in any of the
three phases considered. As only the highest of the phase current is considered, it is also
possible to use one single-phase current as well as two-phase currents. In these cases, the
currents that are not used will be zero.
• For I3P2 and V3P2 the setting alternatives are: any individual phase current/voltage, as well as
any combination of phase-phase current/voltage or the positive sequence current/voltage.
Thus, single-phase as well as, phase-phase or three-phase feeding on the LV-side is possible
but it is commonly selected for current and voltage.
Application manual
Section 13
Control
SEMOD159053-35 v4
SEMOD159053-61 v4
SEMOD159053-65 v6
335