%THD-F: Total Harmonic Distortion with respect to Fundamental frequency
%THD-F = ( √ (V2
2
2
+ ... +V49
+ V3
Where,
V1: magnitude at the nominal frequency (eg.50 or 60 Hz)
V2: magnitude at the second harmonics
...
V50: magnitude at the 50-th harmonics.
2
2)
+ V50
) / V1) * 100
14