11
KON-215-60-33.2-v.1.0-E
RFD TEHNICAL DESCRIPTION.doc
can be activated separately. In addition, a
request in case of TC failure is the need to block
the breaker closing next to the failed TC.
Breaker closing blockade, on given command
and with TCS function, is achieved by setting
TC
fail blk.
to state ON.
Figure 11. Secondary trip circuit failure supervision
Transformer thermal supervision by
temperature measurement
(23 Therm. sup.)
The function of thermal supervision of the
transformer
temperature
by
measurement
allows continuous monitoring of the temperature
in seven points using RTD elements. The
measured resistance values from each of the
connected RTD elements are processed in
seven equal mutually independent algorithms.
The choice of two levels of settings for each
element enabling applications in various plants.
Measured temperature values are available to
users via the HMI interface and via serial
communication interfaces. Detecting errors in
one of the connected RTD elements generates
information errors and blocking the issuance of
the signal pickup.
Apparatus wear monitoring
Circuit breaker wear monitoring function, which
is usually performed as an additional function in
the relay protection, gives a good enough insight
into the MV circuit breaker, and as such allows
the rationalization of maintenance costs. Circuit
breaker wear usually depends on the tripping
current and therefore tripping currents in all
three phases are taken as measuring inputs of
the specified function. With circuit wear
monitoring over current an overview of the
number of trips, operating time and number of
manipulations for all other apparatus is given.
Transformer energization detection
(InRush)
When energizing the power transformer, the
energizing currents can surpass nominal values
by ten times. As this is a brief transition event,
this state is not considered a failure. The typical
attribute of this state is the emersion of second
harmonic inrush current in energization current.
The Inrush function for such event detection
measures the size of second harmonic and uses
it to block overcurrent protections, ground
current protection and limited low impedance
ground current protection which could in cases
like these, result in unwanted trip.
Time synchronization
In order to keep internal relay time synchronized
with the time of other relays in the facility,
remote synchronization using communications
(SCADA) or the provided binary input prepared
for IRIG-B time code is enabled.Time setting is
possible using software support or using the
front panel. The integrated battery backup
allows undisturbed work of the clock mechanism
even
after
auxiliary
power
failure
or
disappearance.
Complete
adjustment
to
facility
equipment
The circuit and software architecture of
protective relays allows adjustment of protection
to implemented measurement transformers and
switches
in
the
facility.
Circuit
breaker
tripping/closing is often realized using auxiliary
relays, therefore it is sometimes necessary to
ensure a sufficient time interval for trip/close
command impulse. Close command impulse
duration can be adjusted. The factory setting for
trip/close impulse duration is 250ms.
Advanced failure analysis
In order to enable quality event analysis in case
of disturbances or failures in the facility, the
device has an implemented event log list, as
well as a trip log.
Each list can store a maximum of 512 events,
with expansion capability according to the users’
wishes. Events are stored on lists in 2ms
intervals. The selection of events that are to be
stored is chosen via software support.
The integrated battery allows storing of all
events even after auxiliary device power supply
failure or disappearance.
