MI 2792 PowerQ4 Plus
Theory and internal operation
115
Active attribute for particular quantity is set if:
Phase/line RMS value is greater than lower limit of a measuring range (details in
technical specification): voltage and current effective value, harmonics and THD,
voltage flicker.
Type of a load coincides with two- or four-quadrant area (details in
Power and
energy recording
): active, reactive and apparent power, power factor and
displacement power factor.
Frequency and unbalance measurement are always considered as active values for
recording.
Table below show number of signals for each parameter group in RECORDER.
Table 5.4: Total number of recorded quantities
1W
3W
4W
U,I,f
13 quantities
52 values per interval
20 quantities
80 values per interval.
35 quantities
140 values per interval.
Power &
Energy
16 quantities
64 values per interval
12 quantities
48 values per interval
60 quantities
240 values per interval
Flicker
3 quantities
12 values per interval
9 quantities
36 values per interval
9 quantities
36 values per interval
Symmetry
–
2 quantities
8 values per interval
4 quantities
16 values per interva
Harmonics
202 quantities
800
303 quantities
1212 values per interval
416 quantities
1628 values per interval
Interharmonics
202 quantities
800
303 quantities
1212 values per interval
416 quantities
1628 values per interval
Total
235 347
524
Power and energy recording
Active power is divided into two parts: import (positive-motor) and export (negative-
generator). Reactive power and power factor are divided into four parts: positive
inductive (+i), positive capacitive (+c), negative inductive (-i) and negative capacitive (-
c).
Motor/generator and inductive/capacitive phase/polarity diagram is shown on figure
below:
