Blocking; Design - ABB REG650 Technical Manual

1MRK 502 034-UEN -
9.2.7.3
9.2.7.4
Technical Manual
frequency ceases during the delay time, and is not fulfilled again within a defined
reset time, the START output is reset.

Blocking

It is possible to block Over frequency protection (SAPTOF) completely, by binary
input signals or by parameter settings, where:
BLOCK: blocks all outputs
If the measured voltage level decreases below the setting of MinValFreqMeas in
the preprocessing function Signal Matrix for analog inputs (SMAI), both the
START and the TRIP outputs, are blocked.

Design

The frequency measuring element continuously measures the frequency of the
positive sequence voltage and compares it to the setting StartFrequency. The
frequency signal is filtered to avoid transients due to switchings and faults in the
power system. The design of Over frequency protection (SAPTOF) is
schematically described in figure 134.
BLOCK
freqNotValid
Frequency Comparator
f > StartFrequency
IEC09000033 V1 EN
Figure 134: Schematic design of overfrequency protection SAPTOF
Frequency protection
BLOCK
OR
START
Definite Time Delay
TimeDlyOperate
TRIP
Section 9
BLKDMAGN
Start
&
Trip
Output
Logic
START
TRIP
IEC09000033-1.vsd
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