The synchronizing function compensates for the measured slip frequency as well as the circuit
breaker closing delay. The phase angle advance is calculated continuously. The calculation of
the operation pulse sent in advance is using the measured
SlipFrequency
and the set
tBreaker
time. To prevent incorrect closing pulses, a maximum closing angle between bus and line is
preset internally to a value of 15 degrees.
Table 26 shows the maximum settable value for
tBreaker
at the preset maximum closing angle of 15 degrees, at different allowed slip
frequencies for synchronizing.
Table 26: Dependencies between tBreaker and SlipFrequency with maximum closing angle of 15 degrees
tBreaker
[s] (max settable value) with the internally
preset closing angle of 15 degrees
SlipFrequency [Hz] (BusFrequency - LineFrequency)
0.040 1.000
0.050 0.800
0.080 0.500
0.200 0.200
0.400 0.100
0.800 0.050
1.000 0.040
The reference voltage can be phase-neutral L1, L2, L3 or phase-phase L1-L2, L2-L3, L3-L1 or
positive sequence (Require a three phase voltage, that is UL1, UL2 and UL3) . By setting the
phases used for SESRSYN, with the settings
SelPhaseBus1
,
SelPhaseBus2
,
SelPhaseLine2
and
SelPhaseLine2
, a compensation is made automatically for the voltage amplitude difference
and the phase angle difference caused if different setting values are selected for the two sides
of the breaker. If needed an additional phase angle adjustment can be done for selected line
voltage with the
PhaseShift
setting.
13.1.2.2 Synchrocheck
M12309-6 v9
The main purpose of the synchrocheck function is to provide control over the closing of circuit
breakers in power networks in order to prevent closing if conditions for synchronism are not
detected. It is also used to prevent the re-connection of two systems, which are divided after
islanding and after a three pole reclosing.
Single pole auto-reclosing does not require any synchrocheck since the system
is tied together by two phases.
SESRSYN function block includes both the synchrocheck function and the energizing function
to allow closing when one side of the breaker is dead. SESRSYN function also includes a built in
voltage selection scheme which allows adoption to various busbar arrangements.
IEC04000179 V1 EN-US
Figure 88: Two interconnected power systems
Figure 88 shows two interconnected power systems. The cloud means that the
interconnection can be further away, that is, a weak connection through other stations. The
Section 13 1MRK 511 358-UEN A
Control
226
Application manual
To Next Page
Loading...
