Siemens SINAMICS S120 System Manual page 80

Commissioning
7.4 Commissioning example for an infeed with voltage and frequency control for an island grid.
Parameter Value
p5494[0] e.g. 93 %
p6420[0]
1)
p6421[0]
1)
Additional parameter settings for a black start
p5580 e.g. 2
p5581[0] e.g. 2 s
80
Comment
Magnetizing scale values
The adjustable parameter defines the percentage of the rated voltage for trans-
former magnetization. In practice, the ideal value of 100 % is generally not re-
quired. This is because a small step-like residual magnetization when closing the
circuit breaker does not result in any inadmissible settling currents.
Especially in the case of an external DC link pre-charging system via a separate
DC circuit may mean that reduced magnetization is required, if the achievable
magnitude of the DC link voltage is not sufficient to provide 100 % transformer
magnetization. It should be ensured that during magnetization, the Active Line
Module modulation depth does not reach the overmodulation range
(r0074 > 100 %), in order to avoid harmonic currents and DC current compo-
nents.
Grid transformer phase shift, infeed transformer
Enter the phase shift of the grid transformer. Vector group Dy5 => -150° (is de-
termined more precisely with transformer identification p5480 = 12).
For the successful transformer identification in mode p5480 = 12, the coarse
setting must be made manually (also see the following chapter on transformer
commissioning).
Note: With the circuit breaker closed at the infeed transformer, a correct setting of
p6420[0] and p6421[0] can be identified by the fact that the characteristics with
respect to time of voltages r3468[0, 1] and r5488[0, 1] approximately coincide for
low load conditions.
Grid transformer gain adaptation, infeed transformer
(Is determined more precisely with transformer identification p5480 = 12).
For successful transformer identification in mode p5480 = 12, the coarse setting
must be made manually (also see the following chapter on transformer commis-
sioning).
Island grid black start mode
A black start designates establishing a voltage in a grid that initially was in a no
voltage condition. It must be ensured that the supply for the power generating
system itself must be ensured on the plant side before the black start.
For a black start (p5580 = 2) initially, a check is made as to whether the island
grid is in a no-voltage condition, before the circuit breaker between the infeed and
the island grid is closed. The infeed voltage is then increased until the rated volt-
age is reached in the island grid. An automatic black start can be set using
p5580 = 3.
If the island grid is already at a certain voltage level, then an immediate switch is
made into grid droop operation (standard switching to an existing grid). Other-
wise, a black start is realized.
Island grid times, black start voltage ramp duration
Sets the ramp duration for the grid voltage.
System Manual, 04/2015, A5E03347436A
Grid infeed