WAGO I/O System 750 XTR
Function Description 39
750-495/040-010 3-Phase POM 20KV 300A XTR
Manual
Version 1.0.0
Active power minimum and maximum values are determined over a configurable
time interval (WAGO-I/O-
CHECK
or parameters 37, 38 and 39).
In real networks, not all loads are purely resistive. Phase shifting occurs between
the current and voltage. However, this does not affect the method for determining
the RMS values for current and voltage previously described. The I/O module
calculates both the reactive power (Q) and the apparent power (S) for each
phase.
The total active power (P), total reactive power (Q) and total apparent power (S)
are calculated as follows:
P
total
= P1 + P2 + P3
Q
total
= Q1 + Q2 + Q3
S
total
= S1 + S2 + S3
These calculations are only performed in WAGO-I/O-
CHECK
and CODESYS
function blocks and cannot be exported through the process image.
Calculation of Energy
Time-based integration of power yields the level of energy for each phase. The
I/O module provides the values for active, reactive and apparent energy. Values
for the individual phases and a total value are provided both for active and
reactive energy; only the fundamental components are included in the measured
value for the reactive energy. A distinction can also be drawn between import and
export of active energy and capacitive and inductive reactive energy (see figure
below).
Figure 8: Assignment of Active and Reactive Energy in the 4 Quadrants
The values of all energy meters are saved in the I/O module. These operate
internally with the resolutions mWh / mVARh / mVAh and are reset when a value
of 9,999,999,999 kWh (kVARh, kVAh) is exceeded.
