Siemens SICAM P 7KG7750 - Page 45

3
3.2 Formulas and Calculation of Derived Quantities
45Power Meter SICAM P 7KG7750/55, Manual
E50417-B1076-C340-A6, Edition 09.2013
Line Derived Quantity Formula Note
18 System frequency
P
T
N
f =
Refer to note 1
19 Active energy demand
0
1
>=
∑
=
PforPW
ν
ν
The active energy demand will
be calculated every second.
20 Active energy supply
0
1
<=
∑
=
PforPW
ν
ν
The active energy supply will
be calculated every second.
21 Active energy without sign
∑
=
=
1 ν
ν
PW
Calculation without sign
22 Active energy net demand
∑
=
=
1 ν
ν
PW
Calculation with sign
23 Asymmetrical voltage U or
current I
M
G
V =
Refer to note 2
Range is 0 to ∞, avoid division
by 0!
24 THD voltage, current
1
1
−=
M
M
THD
tot
Refer to note 3
25 Harmonics From Fourier transformation