ABB RELION REX640 - 10.4.5.3 Percentile calculation; 10.4.5.4 Observation period

The activation of the BLOCK input blocks MN_UNB_AL output.
10.4.5.3 Percentile calculation
The Percentile calculation module performs the statistics calculation for the level
of voltage unbalance value for a settable duration. The operation of the Percentile
calculation module can be described with a module diagram.
Observation
period
Statistics
recorder
Percentile
calculator
PCT_UNB_AL
OBS_PR_ACT
BLOCK
10MIN_MN_UNB
(from Average calculator)
3s_MN_UNB
(from Average calculator)
Figure 980: Percentile calculation
10.4.5.4 Observation period
The Observation period module calculates the length of the observation time for
the Statistics recorder sub-module as well as determines the possible start of a new
one. A new period can be started by timed activation using calendar time settings
Obs period Str year , Obs period Str month , Obs period Str day and Obs period Str
hour .
The observation period start time settings
Obs period Str year , Obs
period Str month , Obs period Str day and Obs period Str hour are used
to set the calendar time in UTC. These settings have to be adjusted
according to the local time and local daylight saving time.
A preferable way of continuous statistics recordings can be selected over a longer
period (months, years). With the Trigger mode setting, the way the next possible
observation time is activated after the former one has finished can be selected.
Table 1643: Trigger mode observation times
Trigger mode Observation time
Single Only one period of observation time is activated.
Periodic The time gap between the two trigger signals is seven days.
Continuous The next period starts right after the previous observation
period is completed.
The length of the period is determined by the settings Obs period selection and
User Def Obs period . The OBS_PR_ACT output is an indication signal which exhibits
rising edge (TRUE) when the observation period starts and falling edge (FALSE)
when the observation period ends.
If the Percentile unbalance , Trigger mode or Obs period duration settings change
when OBS_PR_ACT is active, OBS_PR_ACT deactivates immediately.
1MRS759142 F
Power quality measurement functions
REX640
Technical Manual
1851