1.
Connect single-phase or three-phase test set to inject the operating voltage. The
injection is done across the measuring branch.
The required trip and alarm voltage, as well as the used stabilizing
resistance value must be set in the function. Note as well that used CT
input in the IED must have ratio set as 1:1. This is essential for the
measurement of the expected value. Normally a slightly higher operating
value is no problem as the sensitivity is not influenced much.
2.
Increase the voltage and make note of the operate value
U>Trip. This is done by manual
testing and without trip of the test set.
3.
Connect the trip contact to the test set to stop the test set for measurement of trip
times below.
4.
Reduce the voltage slowly and make note of the reset value. The reset value must be high
for this function.
5.
Check the operating time by injecting a voltage corresponding to 1.2
ˣ
U>Trip level. Make
note of the measured trip time.
6.
If required, verify the trip time at another voltage. Normally 2
ˣ
U>Trip is selected.
7.
If used, measure the alarm level operating value. Increase the voltage and make note of
the operate value
U>Alarm. This is done with manual test and without trip of the test set.
8.
Measure the operating time on the alarm output by connecting the stop of the test set to
an output from
tAlarm. Inject a voltage 1.2
ˣ
U>Alarm and measure the alarm time.
9.
Check that trip and alarm outputs operate according to the configuration logic.
10. Finally check that start and alarm information is stored in the event menu and if a serial
connection to the SA is available verify that the correct and only the required signals are
presented on the local HMI and on the SCADA system.
Information on how to use the event menu is found in the operator's manual.
12.3.2.2
Completing the test
SEMOD55257-73 v4
Continue to test another function or end the test by changing the
TestMode setting to Off.
Restore connections and settings to their original values, if they were changed for testing
purposes.
12.3.3
SEMOD155702-45 v4
12.3.3.1
Generator differential protection GENPDIF
Prepare the IED for verification of settings outlined in
section
"Requirements" and section "Preparing for test" in this chapter.
Verifying the settings
SEMOD155702-49 v4
1.
Go to Main menu/Test/Function test modes/Differential protection and make sure all
other functions, configured to the same current transformer inputs as the generator
differential protection, are set off. Make sure that the generator differential function is
unblocked.
2.
Connect the test set for injection of three-phase current to the current IEDs, which are
connected to the CTs on the HV side of the generator.
3.
Increase the current in phase L1 until the protection function operates and note the
operating current.
4.
Check that trip and alarm contacts operate according to the configuration logic.
5.
Decrease the current slowly from operate value and note the reset value.
Section 12
1MRK 502 067-UEN B
Testing functionality by secondary injection
100
Commissioning manual
