Siemens SINAMICS G130 Engineering Manual page 29

Fundamental Principles and System Description
Engineering Information
Division of all supply voltage dips according to magnitude and duration in the ranges
A - F for the description of the behaviour of SINAMICS drives with unregulated Infeeds
Range A
Range A comprises supply voltage dips, the magnitude of which is in the long and short-term ranges of permissible
supply voltage variations.
Dips in range A are, therefore, permissible, with the restriction that the DC link voltage and the drive power decrease
in proportion to the magnitude of the supply voltage dips.
Range B
≈ 0.75. The DC link
Range B comprises supply voltage dips, the magnitude of which reaches values of V /V
Line N
voltage which is in proportion to the supply voltage is still over the under-voltage trip level in the DC link but the
auxiliaries which are supplied with 230 V by the internal transformer do not function any more after a few
milliseconds.
Dips in range B are, therefore, only permissible when the supply of the auxiliaries with 230 V is done via a secure,
external source. It must also be taken into consideration that the DC link voltage and the drive power decrease in
proportion to the magnitude of the supply voltage dip.
Range C
Range C comprises very short supply voltage dips of any magnitude, the duration of which is up to 5 ms. During this
time, the current required by the load is delivered entirely by the DC link capacitors, thus causing the DC link voltage
to decrease. As a result of the extremely short duration of the dip, the DC link voltage still does not reach the under-
voltage trip level, even at 100 % load. The auxiliaries supplied with 230 V also remain in operation.
Dips in range C are, therefore, as a result of the extremely short duration, permissible without restrictions.
Range D
Range D comprises very short supply voltage dips of any magnitude, the duration of which is up to 10 ms. During this
time, the current required by the load is delivered entirely by the DC link capacitors, thus causing the DC link voltage
to decrease. The DC link voltage then only does not reach the under-voltage trip level, if the DC link is discharged
more slowly than in range C. Therefore, the drive can be operated with a maximum load of approx. 50 %. Due to the
still relatively short duration, it can be assumed that the auxiliaries which are supplied with 230 V will remain in
operation.
Dips in range D are, therefore, as a result of the very short duration, permissible, as long as the drive is operating at
partial load with a maximum of 50 %.
SINAMICS Engineering Manual - May 2008
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