Hitachi Relion 650 Series Technical Manual page 294

Section 12
Monitoring
IEC19000914 V1 EN-US
Figure 127: Electrical monitoring of CB closing, shown for current feedback
The monitored quantities are evaluated from the electrical feedback signal selected by
FeedbackSigC. Based on the detected instant of inception, the electrical making time is evaluated as
the time difference between the instant of controlled close command (CCLCMDLX) and the current
inception instant as shown in
Similarly, the actual pre-strike angle is evaluated as summation of the predicted pre-strike angle and
difference of actual and predicted electrical making times.
The inception instant is determined based on the settings CloseCThreshold and CloseFThreshold.
Both settings are defined in percent of global base values
Using the absolute values of CloseCThreshold and CloseFThreshold, the inception instant is
detected as shown in
Voltage
Current
CCLCMDLX
IEC19000759 V2 EN-US
Figure 128: Detection of current inception instant
288
Electrical making
Close
time
command
Figure 127.
Figure 128 and
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Pre-strike Angle
(Section
Figure 129.
Inception instant
1MRK 511 557-UEN Rev. A
Time(t)
Time(t)
1EC19000914-1-en.vsdx
12.18.7.3).
CloseCThreshold
CloseFThreshold
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