ABB RELION REX640 Technical Manual page 1440

Section 9
Control functions
1434
PH DIFF MEAS _ _
= ∠
GUID-10637261-4349-40DC-B482-013CC043D77D V1 EN
∠U Measured bus A side voltage phase angle
BusA
∠U Measured bus B side voltage phase angle
BusB
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
• 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 1370: Additional conditions for the Synchro check
Measurements
U_DIFF_MEAS
PH_DIFF_MEAS
FR_DIFF_MEAS
Estimated closing angle
U U Phase shift
− ∠ +
BusA BusB
Synchrocheck mode
"Synchronous"
< 0.01 x Nominal voltage (U
< 5 degree
< 0.001 x Nominal frequency (f
N/A
1MRS759142 C
(Equation 333)
).
n
"Asynchronous"
) < Difference voltage
n
< Difference angle
) < Frequency difference
n
< Difference angle
Technical Manual
REX640