17-8
IM CW240E
Harmonic Measurement Basic Equations
∑
50
n
=2
Measurement Item
Equations
Voltage RMS Value
Current RMS Value
RMS Value nth Order Content
Total Harmonic Distortion Ratio
(Fundamental Wave Standard)
Total Harmonic Distortion Ratio
(Total RMS Value Standard)
100%
RMS Value Phase Angle
(Fundamental Wave Standard)
Un
(nth order harmonic voltage phase) - (fundamental wave phase)
n
In
(nth order harmonic voltage phase) - (fundamental wave phase)
n
fundamental wave rms value
nth order rms value
Un
=
2
(
Unr)
2
(
Uni)
2
In
=
2
(
Inr)
2
(
Ini)
2
THD
F
=
(fundamental wave voltage (current) rms value)
2
(nth order harmonic voltage (current) rms value)
2
THD
R
=
(nth order harmonic voltage (current) rms value)
2
= tan
–1
(
)
{
tan
–1
(
)}
n
Uni
Unr
U
1
i
U
1
r
RMS Value Phase Angle
(U1 Standard)
Un
(nth order harmonic voltage phase)
In
(nth order harmonic current phase)
= tan
–1
(
)
Uni
Unr
= tan
–1
(
)
Ini
Inr
= tan
–1
(
)
{
tan
–1
(
)}
n
Ini
Inr
I
1
i
I
1
r
∑
50
n
=2
(nth order harmonic voltage (current) rms value)
2
∑
50
n
=1
17.1 CW 240 Specifications