eMS sub.net TCP

needleorderNetworking and Communications

Oct 24, 2013 (3 years and 7 months ago)

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eMS






sub.net


TCP



(Trip Coil Pr
o
file)




sub.net


TCP

is a portable instrument for testing both
the circuit
breaker mechanism

and

the

substation batteries. It can be used during
routine maintenance or on a continuous basis if a problem is suspected.
Recording the profile of the trip and close coil current pulses is a
recogni
sed way of detecting actual or evolving faults on a circuit breaker.
The tripping battery can be monitored to detect any problems with the
cells, connections or cables.


The system is housed in a small, rugged suitcase style enclosure which
includes the po
wer, signal and communications cables. A compact
programmer is available for configuring
sub.net
-

TCP

and viewing the
test reports.


sub.net


TCP

is easy to use and only requires two input connections.
Once connected a complete substation can be tested
without having to
reconnect to each circuit breaker.
Sub.net


TCP

will automatically
record, analyse and report on each trip and close operation and will send
these reports to a central location for viewing and archiving via a PSTN or
wireless modem.





C
onnections


Two input signal connections are used: the battery current and voltage. A
clamp style Hall effect

probe is clipped round the battery conductor that
powers all the circuit breaker coils. The direction of current is marked on
the side of the probe. Fused test leads are provided to connect to the
positive and negative legs of the battery.


If a PSTN mod
em is being used the telecom cable is connected from the
socket marked
Modem

to a BT phone socket. If a wireless modem is
being used the antenna is connected to the socket marked
GSM

and then
placed where a good mobile phone signal is available.

Test repo
rt


The breaker test reports include graphs and measurements of the trip or
close coil pulse and battery voltage dip. Additionally the source data can
also be sent in COMTRADE or CSV format if further analysis is required.




The maximum coil current,
pulse width and battery source impedance are
measured and limits can be set to flag a potential problem.




Example of a slow breaker


This example shows a trip coil pulse where the operate time has been
extended due to a fault and maintenance on the break
er is required. The
graph uses the RMS recording mode which shows longer term events. The
grey sections are also displayed using the high speed waveform recording
mode as shown above.







The graph indicates that the problem lies at the latter stage o
f the
breaker operation between the trip release point and the auxiliary contact
operation. This will help to minimise the repair time by highlighting area
of interest.