3.4 Primary Commissioning Tests with the Generator
387
7UM62 Manual
C53000-G1176-C149-3
−
Read out the motoring power with polarity (negative sign) in the operational
measured values and note it down as P
1
(see table below).
−
Read out the reactive power with polarity (positive sign) in the operational
measured values and note it down as Q
1
(see table below).
3. If possible reduce excitation to approximately 0.3 times rated apparent power of
generator (underexcited).
−
Read out the motoring power with polarity (negative sign) in the operational
measured values under and note it down as P
2
(see table below).
−
Read out the reactive power with polarity (negative sign) in the operational
measured values and note it down as Q
2
(see table below).
4. Adjust generator to no-load excitation and shut down or select the desired
operational state.
Figure 3-37
Determination of the Correction Angle W0
The read-out measured values P
1
, and P
2
are now used to carry out angle error
correction. Calculate according to the following formula:
The power values must be inserted with their correct polarity as read out!
Otherwise faulty result!
This angle
ϕ
corr
is entered with reversed sign as the new correction angle under
address
New setting
= –
ϕ
corr
A quarter of the sum of the measured values P
1
+ P
2
is set as pick-up value of the
reverse power protection
under address
3.4.10.3 Calibrating the Reverse Power Protection
If the generator is connected with the network, reverse power can be caused by
−
closing of the regulating valves,
−
closing of the trip valve
Because of possible leakages in the valves, the reverse power test should – if possible
– be performed for both cases.
Caution!
Underexcitation may cause the generator fall out of step!
Item
Active power
Reactive power
1
P
0
Q
0
2
P
1
Q
1
3
P
2
Q
2
underexcited
overexcited
P/P
N
Q/Q
N
Q
2
Q
1
P
1
P
2
P
0
ϕ
corr
P
1
P
2
–
Q
1
Q
2
–
---------------------
atan
=
