voltage phase, and the minimum or maximum magnitude corresponding to swell
or dip/ interruption during variation is temporarily stored. If the minimum or
maximum is found in tracking and a new magnitude is stored, also the inactive
phase voltages are stored at the same moment, that is, the inactive phases are
not magnitudetracked. The time instant (time stamp) at which the minimum or
maximum magnitude is measured is also temporarily stored for each voltage phase
where variation is active. Finally, variation detection triggers the recorded data
update when the variation activation ends and the maximum duration time is not
exceeded.
The data objects to be recorded for PHQVVR are given in
Table 1632
. There are
totally three data banks, and the information given in the table refers to one data
bank content.
The three sets of recorded data available are saved in data banks 1-3. The data bank
1 holds always the most recent recorded data, and the older data sets are moved to
the next banks (1→2 and 2→3) when a valid voltage variation is detected. When all
three banks have data and a new variation is detected, the newest data are placed
into bank 1 and the data in bank 3 are overwritten by the data from bank 2.
Figure 976
shows a valid recorded voltage interruption and two dips for the
Phase
mode
value "Single Phase". The first dip event duration is based on the U_A
duration, while the second dip is based on the time difference between the dip
stop and start times. The first detected event is an interruption based on the U_B
duration given in
Figure 976
. It is shown also with dotted arrows how voltage time
stamps are taken before the final time stamp for recording, which is shown as a
solid arrow. Here, the U_B timestamp is not taken when the U_A activation starts.
U_A
U_C
U_B
U_A duration
U_B duration
U_B amplitude &
timestamp
U_A amplitude &
timestamp
U_C amplitude & timestamp
Voltage dip set
Voltage swell set
Dip start
Dip stop
Voltage Int set
Figure 976: Valid recorded voltage interruption and two dips
Power quality measurement functions
1MRS759142 F
1840 REX640
Technical Manual
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