Rockwell Automation 1412-PP21xx PowerPad Portable Powermonitor - Manual (Page 86)

86 Rockwell Automation Publication 1412-UM001D-EN-P - September 2012
Appendix C Mathematical Formulas For Various Parameters
Peak Factors for Current and
Voltage
One Second RMS Values for
Voltage and Current
NSS: number of samples in one second (multiple of NSC).
Voltage and Current
Unbalance
[]
[] []
[][ ] ∑
−
=
⋅
=
1
0
2
1
) i Vpm , i max(Vpp
Vcf
NSC
n
n i V
NSC
i Peak factor single voltage i + 1 phase
[]
[] []
[][ ] ∑
−
=
⋅
=
1
0
2
1
) i Upm , i max(Upp
Ucf
NSC
n
n i U
NSC
i Peak factor phase-phase voltage i + 1 phase
[]
[] []
[][ ] ∑
−
=
⋅
=
1
0
2
1
) i Apm , i max(App
Acf
NSC
n
n i A
NSC
i Peak factor current i + 1 phase
[]
[][ ] ∑
−
=
⋅
= 1
0
2
1 Vrms
NSS
n
n i V
NSS
i
Single rms voltage i + 1 phase
[]
[][ ] ∑
−
=
⋅
= 1
0
2
1 Urms
NSS
n
n i U
NSS
i
Compound rms voltage i + 1 phase
[]
[][ ] ∑
−
=
⋅
= 1
0
2
1 Arms
NSS
n
n i A
NSS
i
Rms current i + 1 phase
=
V
+
(VF[0] + a VF[1] + a 2 VF[2]) Direct voltage (complex notation a = e )
1
3
j 2π
3
=
V
-
(VF[0] + a 2 VF[1] + a VF[2]) Reverse voltage
1
3
Vrms
-
Vrms
+
Arms
-
Arms
+
Vunb = , Aunb =