ABB SYNCHROTACT 5 - Page 39

Operating Instructions SYN 5201/SYN 5202
Document No Art Part Language Revision page
abb
ABB Switzerland Ltd
3BHS109762 E01
en D 39
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d) Paralleling of asynchronous lines:
If two lines do not form a ring connection, the slip limits are restricted by the current
limit permitted after paralleling. If the flow of power in a particular direction is to be
avoided, the corresponding slip limit must be set to zero.
Angle limit, negative -max and positive +max
The permissible angle limit is based on different criteria, depending on the application:
a) paralleling of asynchronous sources.
b) paralleling of synchronous sources.
a) Paralleling of asynchronous sources:
The maximum permissible angle limit ±
max should generally be set symmetrically and
to 10 DEG.
If 3,6
*
fn
*
smax
*
t on+3 > 10 DEG, the value should be rounded up to whole degrees.
Setting values above 15 DEG are not usual. If the calculation produces such a result, it
should be checked whether the maximum slip can be reduced.
b) Paralleling of synchronous sources:
The coupling reactance x
K
in ring mains lines and the balancing current I
K
flowing
through these cause a phase shift between the two voltages U1 and U2.