By default AQ-200 series protection IED
Autorecloser function is able to generate only one final trip signal without
differentiating between different requests or protection stages. Final trip
signal is also not generated at all when autoreclosing is disabled. But it is
possible to build this kind of functionality by using the logic editor. The
following chapter shows how to do it.
First set up the Logical Output signals for
the final trip signals.
Then in logic editor build logic as seen in above image
for each final trip signal. When this is done each of the logical outputs set
up can be used for indicating protection stage final trips locally with LEDs or
through RTU. Next up is the explanation of each part.
The logic has two branches for situations where
autorecloser is either ON or OFF. Autorecloser will not make any final trip in
case the function is switched OFF by a programmable control switch (or by
digital input or other signal). For this reason the upper branch is made to get
a final trip signal in case autorecloser is disabled. “AR On” is a signal
generated by Autorecloser. This signal is added to equation with NOT gate to
prevent final trip signal from being generated during the first trip shots when
autorecloser is in use.
The lower branch in the lower branch I> Trip signal
is connected through SR gates S (Set) input which activates the output. After
the output of the SR-gate has been activated the logic chain will begin to wait
for the “AR Final Trip” signal to be generated by autorecloser function. When
autorecloser generates the signal “LO2 Final.Trip.I>” logical output will
activate. Delay gate should be used so
that SR gate input R (Reset) has the time to reset the SR gate output after the