Iskra MT440 - Page 59

AppendixB:Calculations&equations
User’sManual 55
THD
()
100
I
In
%THDI
1
63
2n
2
f
⋅=
∑
=
Current THD
I
1
− value of first harmonic
n − number of harmonic
()
100
U
Un
%THDU
1
63
2n
2
f
⋅=
∑
=
Phase voltage THD
U
1
− value of first harmonic
n − number of harmonic
()
100
U
Un
%THDU
1
63
2n
2
ff
⋅=
∑
=
Phase-to-phase voltage THD
U
1
− value of first harmonic
n − number of harmonic
Energy
exponent price Tarif
10 Price in tariff Price ⋅=
Total exponent of tariff price and energy
price in all tariffs