modes/Voltage/OEXPVPH(24,U/f>)/OEXPVPH:1
for the function, or for each
individual function in a chain, to be tested next. Remember to set the parameter
Blocked
to
Yes
, for each individual function that has been tested.
6.6.5
100% Stator earth fault protection, 3rd harmonic based
STEFPHIZ
Prepare the IED for verification of settings as outlined in
Values of the logical signals for STEFPHIZ are available on the local HMI under
Main menu/Tests/Function status/Voltage/STEFPHIZ(59THD)/STEFPHIZ:1
.
The Signal Monitoring in PCM600 shows the same signals that are available on the
local HMI.
6.6.5.1
Testing
The protection function uses measurement of the third-harmonic voltages in the
neutral point of the generator and on the generator terminal (broken delta voltage
transformer connection to the IED).
The test set shall be capable to generate third-harmonic voltages. One voltage (U
N3
)
is connected to the residual voltage input related to the terminal side of the generator.
The second voltage (U
N3
) is connected to the voltage input related to the neutral of the
generator. The angle between the injected third-harmonic voltages shall be adjustable.
en07000127.vsd
U
3N
U
3T
IEC07000127 V1 EN
Figure 18:
Typical phasor diagram for third harmonic voltages for healthy
machine
1.
Inject the following voltages: U
3T
= 15 V, U
3N
= 5 V and the angle between the
voltages = 180°. Check the monitored values of the following analogue signals:
E3 (the magnitude of the third-harmonic induced voltage in the stator), U
3N
: 5 V
(the magnitude of the third-harmonic voltage measured at the neutral side of the
generator), U
3T
: 15 V (the magnitude of the third-harmonic voltage measured at
the terminal side of the generator) and ANGLE: 180° (the angle between the
Section 6
1MRK 502 049-UEN A
Testing functionality
86
Commissioning manual
