Reference Manual
Power Analyzer EMM5
Rev. 11
2018-07
6
2.2
Measurement values
The measurement system uses the information from the data collection system to calculate the values of the power
grid.
Values, which are directly calculated from the raw input data:
ULN : TRMS values for the voltages L1-N, L2-N, L3-N
ULL : TRMS values for the voltages L1-L2, L2-L3, L3-L1
I : TRMS values for the currents L1, L2, L3, (N)
If : RMS values for the current fundamentals L1, L2, L3, (N)
P : TRMS active power P for L1, L2, L3 and sum L1+L2+L3
Q :TRMS reactive power Q for L1, L2, L3 and sum L1+L2+L3
Harmonics (in percent of fundamental wave) for all currents and voltages
phi : Angle between fundamental waves of current and voltage of a phase (L1, L2, L3)
cp : cos-
for fundamental waves of L1, L2, L3
f : Frequency of voltage L1-N
From these, further calculations are possible:
THD-U : THD for each voltage channel from the harmonics 1-62
THD-I : THD for each current channel from the harmonics 1-62
Pth / Ith : Exponentially damped values for currents and active powers which resemble the behaviour of
thermal measurement
S : TRMS apparent powers S from P and Q of each phase and for power sums
pf : Power factor as the absolute quotient P/S for each phase. It includes the influence of harmonics, because
it is calculated from TRMS values P and S. If the harmonic-free information is needed, use the fundamental cp
values! The power factor is unsigned!
Additional values by numeric integration:
For active powers P-L1, P-L2, P-L3 and P-sum, an energy accumulator is available, which separately counts the amount
of energy for import and export direction (in kWh). The same counter is available for the reactive power readings Q-L1,
Q-L2, Q-L3 and Q-sum. These are accumulated separately for inductive and capacitive reactive power. For devices with
