Everfine PF9810 - Page 21

PF9800SeriesUser'sManual
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20
componenttothatofthefundamental(the1storder).Thecomputationequationsare
asfollows:
%100
U
)U(
thdU
1
n
2k
2
k
×=
∑
=
or
%100
I
)I(
thdI
1
n
2k
2
k
×=
∑
=
%100
U
U
U
1
k
k%
×=
or
%100
I
I
I
1
k
k%
×=
CSAmethod(

)
：
Computestheratioofthermsvalueofthe2ndto50thordercomponenttothatofthe
rmsvaluethe1stto50thcomponent.Thecomputationequationareasfollows:
%100
)U(
)U(
thdU
n
1k
2
k
n
2k
2
k
×=
∑
∑
=
=
or
%100
)I(
)I(
thdI
n
1k
2
k
n
2k
2
k
×=
∑
∑
=
=
%100
)U(
U
U
n
1k
2
k
k
k%
×=
∑
=
or
%100
)I(
I
I
n
1k
2
k
k
k%
×=
∑
=
WhereUthdorIthd:thetotalharmonicdistortionofvoltageorcurrent
U1orI1
：
theeffectivevalueof fundamental frequency(thefirst
harmonic)ofvoltageorcurrent;
UkorIk： theeffectivevalueofkthharmonicof
voltageorcurrent;
Uk%orIk%：therelativevalueofkthharmonicof
voltageorcurrent;
k：harmonicorder;
n
：
themaximumharmonicordersetbyuser,n=50.
(2)Calculationmethodoftotalharmonicvoltage,currentandpower
Totalharmonicvoltage
：
∑
=
=Σ
n
1k
2
k
)U(U
Totalharmoniccurrent
：
∑
=
=Σ
n
1k
2
k
)I(I