Siemens SIPROTEC 7SJ61, Руководство пользователя, Страница: 230 / 454

Functions
2.17 Auxiliary Functions
SIPROTEC, 7SJ61, Manual
C53000-G1140-C210-1, Release date 02.2008
230
2.17.4 Average Measurements
The long-term averages are calculated and output by the 7SJ61.
2.17.4.1 Description
Long-Term Averages
The long-term averages of the three phase currents
I
x
, and the positive sequence components
I
1
for the three
phase currents are calculated within a set period of time and indicated in primary values.
For the long-term average values mentioned above, the length of the time window for averaging and the fre-
quency with which it is updated can be set.
2.17.4.2 Setting Notes
Average Calculation
The selection of the time period for measured value averaging is set with parameter
8301 DMD Interval
in
the corresponding setting group from A to D under MEASUREMENT . The first number specifies the averaging
time window in minutes while the second number gives the frequency of updates within the time window.
15
Min., 3 Subs
, for example, means: Time average is generated for all measured values with a window of 15
minutes. The output is updated every 15/3 = 5 minutes.
With address
8302 DMD Sync.Time
, the starting time for the averaging window set under address
8301
is
determined. This setting specifies if the window should start on the hour (
On The Hour
) or 15 minutes later
(
15 After Hour
) or 30 minutes / 45 minutes after the hour (
30 After Hour
,
45 After Hour
).
If the settings for averaging are changed, then the measured values stored in the buffer are deleted, and new
results for the average calculation are only available after the set time period has passed.
2.17.4.3 Settings
Addr. Parameter Setting Options Default Setting Comments
8301 DMD Interval 15 Min., 1 Sub
15 Min., 3 Subs
15 Min.,15 Subs
30 Min., 1 Sub
60 Min., 1 Sub
60 Min.,10 Subs
5 Min., 5 Subs 60 Min., 1 Sub Demand Calculation Intervals
8302 DMD Sync.Time On The Hour
15 After Hour
30 After Hour
45 After Hour On The Hour Demand Synchronization Time