Hitachi Relion 650 Series Technical Manual page 311

1MRK 511 557-UEN Rev. A
IEC19000921 V1 EN-US
Figure 140: Adaptive correction of electrical making time
It is recommended to apply only a fraction ("beta factor") of the target error as correction value.
Individual beta factors for electrical and mechanical errors are provided and the total correction value
is calculated as:
ADAPTCLLX
where,
BetaAdjustElec = Adaptive correction factor (setting) for electrical error
BetaAdjustMech = Adaptive correction factor (setting) for mechanical error
Usually, no more than one of these beta factors should be greater than zero.
The evaluated ADAPTCLLX is added to the summation of previous correction values and that result
is used for next controlled closing operation. It is given as an output of the function and also added to
the predicted electrical and mechanical operating time in the next controlled closing operation.
Adaptive correction for opening
For a high voltage circuit breaker, the actual instant of main contact separation cannot be seen as the
primary current is usually interrupted at a natural zero crossing. Hence, adaptive correction for
opening is based on the detection of re-ignitions or re-strikes, assuming that further such events can
be prevented by targeting longer arcing time.
Whenever a re-ignition or re-strike is detected (see
is increased by 1 ms (fixed increment). For the next controlled opening operation, this extension
value is added to the target arcing time.
Technical Manual
Operation 1
Target Inception
Actual inception
angle
Error
Operation 2
Actual inception
Target Inception
angle
= BetaAdjustElec · ε
new elec
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= Reference Voltage
= Electrical feedback signal
angle
angle
+ BetaAdjustMech · ε
mech
Section 12.18.7.11.3), an internal extension value
Section 12
Monitoring
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