ABB RELION REX640 - Page 1562

PH DIFF MEAS U U
Gen Bus
_ _ Phase shift= ∠ − ∠ −
(Equation 355)
∠ U
Bus
Measured bus side voltage phase angle
∠ U
Gen
Measured generator side voltage phase angle
Phase shift Setting Phase shift
The synchronism conditions are checked according to several criteria.
• The measured bus and generator voltages are higher than the set value of Live
voltage value (ENERG_STATE equals “Both Live”).
• The measured bus and generator frequencies are both within the range of
95...105 percent of the nominal frequency (fn).
• The measured bus and generator voltages are lower than the set value of
Maximum voltage .
If the
Synchrocheck mode parameter under the Setting menu is set
as "Command", then the SynchroChk Mod Ctl parameter under the
Control menu is used to set values "OFF/Asynchronous". Otherwise, the
Synchrocheck mode parameter under the Setting menu is used to set the
values "Off/Asynchronous".
Some additional conditions must also be fulfilled as per the set Synchrocheck mode .
Table 1516: Additional conditions for the Synchro check
Measurements Synchrocheck mode “Asynchronous”
U_DIFF_MEAS < Voltage Diff Ov Ex and > -Voltage Diff Un Ex
PH_DIFF_MEAS < Angle Diff positive and > - Angle Diff nega-
tive
FR_DIFF_MEAS < Freq Diff OV Synch and > -Freq Diff sub
Synch
Closing angle < Angle Diff positive and >- Angle Diff nega-
tive
Dead voltage value
Live voltage value
Angle Diff negative
U
Bus
U
Gen
Voltage Diff Ov Ex
f
Bus
f
Gen
Frequency[Hz]
∆f = f
Gen
- f
Bus
∆φ =
Voltage Diff Un Ex
Angle Diff positive
Freq Diff Ov SynchFreq Diff sub Synch
∆U = |U
Gen
| – |U
Bus
|
∠
U
Gen
-
∠
U
Bus
Rated Frequency
Figure 856: Conditions to be fulfilled when detecting synchronism between systems
When the measured differences in voltage and frequency are within the synchro
check limits, the output MATCH_OK is activated. The output MATCH_INPRO is active
while the voltage and frequency matching is in progress.
Control functions
1MRS759142 F
1562 REX640
Technical Manual