The calculation window length is set with the
Sliding interval
setting. It has three
window lengths ("3 seconds", "1 minute" or "5 minutes") for sliding mean value
outputs. Output values can also be seen in monitoring.
The window type used for configuration tool output values is always sliding. Output
values are updated once every 0.1 seconds.
Figure 961: Sliding 3 seconds value calculation in principle
The sliding mean values of the fundamental of each phase are SMNH01_A, SMNH01_B
and SMNH01_C. Actual harmonics are seen with their number, for example, phase A
for second harmonic is SMNH02_A and phase C for 9
th
harmonic is SMNH09_C. Direct
current component outputs are SMNDC_A, SMNDC_B and SMNDC_C.
Intervals that are longer than 3 seconds are calculated using free running 3-second
mean values.
The longer 10-minute mean values of the fundamental of each phase are seen in
monitored data as LMNH01_A, LMNH01_B and LMNH01_C. Actual harmonics are
seen with their number. Direct current components are LMNDC_A, LMNDC_B and
LMNDC_C.
Time stamps for ready 10-minute mean value calculation can be seen in the
monitored data L time stamp.
The window type used for the 10-minute mean value calculation is always non-
sliding. The 10-minute value calculation begins based on the protection relay's
internal clock 10 minutes time (for example,11:00, 11:10, 11:20, 11:30, 11:40, 11:50,
12:00…). This is called 10 min tick.
1MRS759142 F
Power quality measurement functions
REX640
Technical Manual
1811
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