Siemens SIPROTEC 7UM62, Manual

Page: 404 / 602

3 Installation and Commissioning
388
7UM62 Manual
C53000-G1176-C149-3
In order to confirm the correct settings, repeat reverse power test again. For this, the
reverse power protection (address
3101
) is set to
BLOCK relay
in order to check its
effectiveness (using the annunciations).
Start up generator and synchronize with network. Close regulating valves.
From the operational measured value for the active power, the motoring power
measured with the device can be derived. 50 % of that value should be taken as the
setting for the reverse power protection.
Increase driving power.
Stop Valve The last test with the stop valve can be performed with a live trip. It is assumed that
the binary input “
>SV tripped
” is marshalled correctly and is controlled by the stop
valve status (by a pressure switch or a limit switch at the stop valve).
Close stop valve.
From the operational measured value for the active power, the motoring power
measured with the device can be derived.
If that value should be found to be less than the reverse power with the stop valves
closed, 50 % of that value should be taken as the setting for the reverse power
protection.
Shut down the generator by activating the reverse power protection on:
Switch
ON
the reverse power protection (address
3101
) and - if used - the forward
power supervision (address
3201
).
3.4.10.4 Checking the Underexcitation Protection
Underexcitation The angle error correction value
CT ANGLE W0
, which has been determined in section
3.4.10.2 and configured under address
0204
for use with the angle error correction,
applies also to the underexcitation protection.
In section 3.4.10.2, the measured values of the reactive power have been read out,
and thus a plausibility check of that measured value with directional check has been
carried out. No further checks are required.
If you choose nevertheless to perform an additional load level measurement and by
this a directional check, proceed as follows:
Check with Load Set the underexcitation protection to
Block relay
(address
3001
).
The proper functioning is checked by approaching freely selected load levels under
overexcited and then underexcited conditions. The plausibility check is carried out by
reading out the relevant operational measured values and comparing them to the
measured values obtained from the station control and protection system.
Switch the underexcitation protection
ON
(address
3001
).
Caution!
Underexcitation may cause the generator to fall out of step, in particular with increased
active power!