Siemens 6MD662, Manual

Page: 45 / 86

Data of the PROFIBUS DP messages
45
SIPROTEC PROFIBUS DP - Bus mapping 6MD662/3/4
C53000-L1840-B011-03
2.3.3 Metered measurands (Counters)
2.3.3.1 Metering values
In the 6MD662/3/4 the metering values (e.g. Wp+, Wq+, Wp-, Wq-) must be:
•
Entered and allocated in the
DIGSI configuration matrix
to:
•
a measured value (e.g. “
3P1_P
”),
•
"Destination system interface" and if required
•
“Metered value window”.
Furthermore, associated parameters (
Conversion factor
,
Restore trigger
and
Energy flow direction
) must be set in the dialog window
Object pro-
perties
of the metered value.
Scaling The scaling of the metered values which are derived from measured values are based
on:
60000 impulse per hour corresponds to
V = V
100 %
and I = I
100 %
or
P = P
100 %
or Q = Q
100 %
V
100 %
, I
100 %
= 100 % value of the measured current in voltage,
P
10 0%
, Q
100 %
= 100 % value of the real or reactive power.
Conversion factor Metered values are transmitted via PROFIBUS DP as "pulse counts" based on the
above mentioned scaling.
A conversion factor must be indicated to the PROFIBUS DP master with which the
number of pulse counts are converted to energy values (e.g. MWh).
This conversion factor which is set during the configuration of the metered values in
DIGSI is used for displaying the metered values in the 6MD662/3/4 and must also be
used for the conversion in the PROFIBUS DP master.
Note:
•
Changes to the routing and scaling of measured values are possible for adaption
to the actual requirements in the substation.
For information in this regard refer to the manual "SIPROTEC Communication
module, PROFIBUS DP - Communication profile" (on page 3).
•
If measured values other than the pre-defined default values are to be transmitted
via PROFIBUS DP, then the position of the measured value that is not required in
the PROFIBUS-DP telegram must be made available by removing the cross ("X")
in the associated column "Destination system interface" of the
DIGSI configu-
ration matrix
.
•
Further information regarding configuration of measured values may be found in
the 6MD662/3/4 device manual.