ABB RELION REX640 Technical Manual page 1411

1MRS759142 C
REX640
Technical Manual
Angle Diff negative
U
Bus
GUID-E45CB802-AC2C-4B2E-B3FC-171DA1F2522B V1 EN
Figure 752: 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.
When the frequency, phase angle and voltage conditions are fulfilled, the duration of
the synchronism conditions is checked to ensure that they are still met when the
condition is determined on the basis of the measured frequency and phase difference.
Depending on the circuit breaker and the closing system, the delay between the
closing signal and the circuit breaker closing is about 50...250 ms. The selected
Closing time of CB informs the function how long the conditions have to persist. The
value covers both circuit breaker closing delay and output type dependent delay. The
synchro check function compensates for the measured slip frequency and the circuit
breaker closing delay. The closing angle advance is calculated continuously:
Closing angle = ∠ U
(
Gen
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∠U Measured generator voltage phase angle
Gen
∠U Measured bus voltage phase angle
Bus
Closing time of CB to be set as in
TCB Parameter
TCB t T x
= CB + PL +
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t Circuit breaker closing delay in ms
CB
T Output type dependent delay in ms (see
PL
x Hardware delays between the protection relay and CB in ms; delays due to, for example, auxiliary
relays and contactors, if used
∠
- ∠U
∆φ
= U
Gen Bus
Angle Diff positive
Voltage Diff Ov Ex
U
Gen
U U
∆ U = | | – | |
Gen Bus
Voltage Diff Un Ex
Live voltage value
Dead voltage value
Freq Diff sub Synch

U f f
) (
− ∠ ° + −
Bus  Gen Bus

Equation 322
Table 1357)
Section 9
Control functions
∆ f f f
= -
Gen Bus
f f
Bus Gen
Freq Diff Ov Synch
Rated Frequency
TCB

 
360 0 °
)
⋅  ⋅


1000
 

Frequency[Hz]
(Equation 321)
(Equation 322)
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