15.4.7.1 Circuit breaker contact travel time
GUID-3AF0EE8D-AA8E-4F83-9916-61B5D0D6B05B v12
The circuit breaker contact travel time subfunction calculates the breaker contact
travel time for opening and closing operations. The operation of the breaker contact
travel time measurement is described in figure
269.
Contact travel
time
calculation
POSCLOSE
POSOPEN
RSTTRVT
Alarm limit
check
BLOCK
BLKALM
TTRVOP
TTRVCL
TRVTOPAL
TRVTCLAL
IEC12000615-2-en.vsd
IEC12000615 V2 EN-US
Figure 269: Functional module diagram for circuit breaker contact travel time
Contact travel time calculation
The contact travel time of the breaker is calculated from the time between the state
of change of auxiliary contacts. The opening travel time is measured between the
opening of the POSCLOSE and closing of the POSOPEN auxiliary contacts.
Similarly, the closing travel time is measured between the opening of the
POSOPEN and closing of the POSCLOSE auxiliary contacts. A compensation
factor has been added to consider the time difference between auxiliary contact
operation and the actual physical opening of the breaker main contact.
tOpent1 t2 t3 tClose t4
Main Contact
POSCLOSE
POSOPEN
0
1
0
1
1
0
tTravelOpen = tOpen + t1 + t2 tTravelClose = tClose + t3 + t4
IEC12000616_2_en.vsd
IEC12000616 V2 EN-US
Figure 270: Travel time calculation
There is a time difference t1 between the start of the main contact opening and the
opening of the POSCLOSE auxiliary contact. Similarly, there is a time difference t2
between the time when the POSOPEN auxiliary contact opens and the main contact
is completely open. Therefore, a correction factor needs to be added to get the
actual opening time. This factor is added with the OpenTimeCorr (t1+t2) setting.
1MRK 505 394-UEN A Section 15
Monitoring
Line differential protection RED650 2.2 IEC 545
Technical manual
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