ABB RELION REX640 - Page 1592

PH DIFF MEAS U U
BusA BusB
_ _ Phase shift= ∠ − ∠ +
(Equation 368)
∠ U
BusA
Measured bus A side voltage phase angle
∠ U
BusB
Measured bus B side voltage phase angle
Phase shift Setting Phase shift
The calculated voltage and phase angle difference values between these voltages
are available as monitored data U_DIFF_MEAS and PH_DIFF_MEAS. The setting
Phase shift is used to compensate the angle shift caused if a power transformer
is located between the voltage measurements.
The synchronism condition and CB closing instance are checked according to
several criteria.
• The measured bus A and bus B voltages are higher than the set value of Live bus
voltage (ENERG_STATE equals “Both Live”).
• The measured bus A and bus B frequencies are both within the range of 95...105
% of the value of the nominal frequency (f
n
).
• The measured bus A and bus B voltages are lower than the set value of Max
energizing V .
When the
Synchrocheck mode setting parameter is set to "Command",
then the “Synchronous”, “Asynchronous” or “Off” condition of the
network across the CB can be set using the SynchroChk Mod Ctl control
command only. If the Synchrocheck mode setting parameter is not set to
"Command", then the Synchrocheck mode setting parameter is used to
set the “Synchronous”, “Asynchronous” or “Off” condition of the network
across the CB.
Some additional conditions must be fulfilled according to the set Synchrocheck
mode .
Table 1530: Additional conditions for the synchro check
Measurements Synchrocheck mode
“Synchronous” “Asynchronous”
U_DIFF_MEAS < 0.01 x Nominal voltage (U
n
) < Difference voltage
PH_DIFF_MEAS < 5 degree < Difference angle
FR_DIFF_MEAS < 0.001 x Nominal frequency
(f
n
)
< Frequency difference
Estimated closing angle N/A < Difference angle
Control functions 1MRS759142 F
1592 REX640
Technical Manual