YOKOGAWA WT310EH - Measurement Functions Used in Harmonic Measurement (Option)

App-4
IM WT310E-01EN
Measurement Functions Used in Harmonic Measurement (Option)
Ir(k)
2
+ Ij(k)
2
I(k) =
Voltage U( ) [V]
Current I( ) [A]
Active power P( ) [W]
P(k) = U
r(k) • Ir(k) + Uj(k) • Ij(k)
Power factor λ ( )
Phase difference
ΦU( ) [°]
Phase difference
Φ I( ) [°]
P(1)
S(1)
λ(1) =
Measurement Function
Methods of Computation and Determination
(Table 1/2)
Ur(k)
2
+ Uj(k)
2
U(k) =
U(k)
2
k = 1
max
U =
I(k)
2
k = 1
max
I =
P(k)
k = 1
max
P =
ΦU(k) = The phase difference
between U(k) and U(1)
ΦI(k) = The phase difference
between I(k) and I(1)
Rms value of
all components
(Total value)
2 to max
(harmonics)
Harmonic order
1
(fundamental wave)
—
—
—
—
Fundamental frequency of the voltage or current set as the PLL source
Phase difference
between I(1) and U(1)
Same as above
(Continued on next page)
PLL source frequency
fU, fI [Hz]
Note
• kdenotesaharmonicorder,rdenotestherealpart,andjdenotestheimaginarypart.
• U(k),Ur(k),Uj(k),I(k),Ir(k),andIj(k)areexpressedusingrmsvalues.
• Theupperlimitofmeasuredharmonicorderisdenotedbymax.maxiseitheranautomaticallydetermined
value or the specified maximum measured harmonic order, whichever is smaller.
• Harmonicmeasurementfunctionsaremeasuredonlyforinputelements,notΣfunctions.
Appendix 1 Symbols and Determination of Measurement Functions