Landis+Gyr E650 Series User Manual page 17

Description of Unit
Reactive energy
D000030110 d – E650 Series 3 (ZMD400AT/CT, ZFD400AT/CT) – User Manual
By summating the mean values of active energy A1, A2 and A3 the micro-
processor calculates the total active energy import +A or the total active
energy export -A.
Mean values
per second
A1
±
å
2
±A
3
±A
Fig. 1.9 Total active energy
The reactive energy values of the individual phases ±R1, ±R2 and ±R3 are
obtained in the combimeters directly from the mean values of reactive
power Q1, Q2 and Q3.
By summating the mean values of reactive energy R1, R2 and R3, the
microprocessor calculates the total positive reactive energy +R or the total
negative reactive energy -R.
Mean values
per second
R1
±
å
2
±R
3
±R
Fig. 1.10 Total reactive energy
The microprocessor can allocate the reactive energy to the 4 quadrants in
the combimeters from the signs of R and A:

Reactive energy in 1st quadrant: +Ri

Reactive energy in 2nd quadrant: +Rc

Reactive energy in 3rd quadrant: –Ri

Reactive energy in 4th quadrant: –Rc
In the same way it can allocate the reactive energy of the individual phases
to the 4 quadrants.
+ kvarh
+Rc
Quadrant II
Export -A
- kWh
Quadrant III
-Ri
- kvarh
-R
Fig. 1.11 4-quadrant measurement
The quadrants are numbered from top right as 1st quadrant (+A/+Ri) anti-
clockwise to the 4th quadrant (+A/–Rc) at bottom right.
Measured quantities
+A (Import)
-A (Export)
Measured quantities
+R
-R
+R
+ kvarh
+Ri
Quadrant I
+A Import
+ kWh
Quadrant IV
-Rc
- kvarh
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© Landis+Gyr AG