ABB SYNCHROTACT 5 - Page 15

Operating Instructions SYN 5201/SYN 5202
Document No Art Part Language Revision page
abb
ABB Switzerland Ltd
3BHS109762 E01
en D 15
Template: CHIND Techn doc stand, A4 P de, R1.DOT; Filename: 3BHS109762E01 D.doc; Print: 12/6/2011 5:48:00 PM; Save: 12/1/2011 2:37:00 PM; CHIND No. 3BHS109763 ZAB D14 Rev. -; I-Q
The monitoring of the paralleling conditions (CHK RELEASE) releases the paralleling
command if the following conditions are fulfilled simultaneously:
 the releasing signal for dead bus (digital input) is issued
 the zero voltage(s) does not exceed the set threshold U0max
 the current voltage does not fall below the minimum voltage
 the current voltage does not exceed the maximum voltage
 the current zero voltage situation corresponds to a configuration permitted by means
of U1not, U2not, 1*2not
 the device is in Operating status (OPERATING)
2.2.4 Command generation
The command generation makes a distinction between asynchronous and synchronous
sources or no-voltage lines. Two modes, one for asynchronous and one for synchronous
sources, run in parallel, so that a source can be asynchronous or synchronous at any
time. The paralleling command is issued in the mode in which all conditions are fulfilled
first.
In SYN 5202 the actuation of the paralleling relays takes place separately in both
channels.
Asynchronous sources
It is called asynchronous sources, if the two lines to be paralleled (or generator and line)
are asynchronous before the circuit breaker is closed.
From the slip s, the acceleration ds/dt, the line frequency f1 and the set paralleling time
t on, the command generation calculates the necessary lead angle
v by which the
paralleling command is shifted forward in time so that the main contacts close exactly on
phase coincidence (see following figure):






 ont
ontdtds
sfv *
2
*/
*1*6,3 
If the measured phase-angle difference
 corresponds to the lead angle v and if all
paralleling conditions are fulfilled at the same time (CHK RELEASE), a command is
generated (COMMAND).
The command length always corresponds to the set paralleling command length
tp on. If
the latter is set to OFF or zero, the command generation is no longer in operation. The
device then functions like a synchrocheck; as soon as the release is given by the
monitoring (CHK RELEASE) the contacts close, when the release is dropped they open
again.