6.5
Testing frequency protection functions
6.5.1
Underfrequency protection SAPTUF
Prepare the IED for verification of settings as outlined in
Values of the logical signals for SAPTUF are available on the local HMI under
Main menu/Tests/Function status/Frequency/SAPTUF(81,f<)/X:SAPTUF
. The
Signal Monitoring in PCM600 shows the same signals that are available on the
local HMI.
6.5.1.1
Verifying the settings
Verification of START value and time delay to operate
1.
Check that the IED settings are appropriate, especially the START value and
the definite time delay.
2.
Supply the IED with three-phase voltages at their rated values.
3.
Slowly decrease the frequency of the applied voltage, until the START signal
appears.
4.
Note the operate value and compare it with the set value.
5.
Increase the frequency until rated operating levels are reached.
6.
Check that the START signal resets.
7.
Instantaneously decrease the frequency of the applied voltage to a value about
20% lower than the operate value.
8.
Measure the time delay of the TRIP signal, and compare it with the set value.
Extended testing
1.
The test above can be repeated to check the time to reset.
2.
The tests above can be repeated to test the frequency dependent inverse time
characteristic.
Verification of the low voltage magnitude blocking
1.
Check that the IED settings are appropriate, especially the
StartFrequency
and the
tDelay
and the
MinValFreqMeas
in the SMAI preprocessing function.
2.
Supply the IED with three-phase voltages at rated values.
3.
Slowly decrease the magnitude of the applied voltage, until the BLKDMAGN
signal appears.
4.
Note the voltage magnitude value and compare it with the SMAI set value
MinValFreqMeas
.
Section 6
1MRK 511 248-UEN -
Testing functionality
64
Commissioning Manual
