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Power Quality Analyzer Model 3945-B
1 sec RMS Values for Voltage and Current
[]
[][ ]
=
=
1
0
2
1
Vrms
NSS
n
niV
NSS
i
Single rms voltage i + 1 phase
[]
[][ ]
=
=
1
0
2
1
Urms
NSS
n
niU
NSS
i
Compound rms voltage i + 1 phase
[]
[][ ]
=
=
1
0
2
1
Arms
NSS
n
niA
NSS
i
Rms current i + 1 phase
NSS:numberofsamplesinasecond(multipleofNSC)
Voltage and Current Unbalance
=
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 =
THD Calculation
Vthd[i] =
[i][n]
Vharm
[i][1]
Vharm
n=2
50
2
Uthd[i] =, ,
[i][n]
Uharm
[i][1]
Uharm
n=2
50
2
Athd[i] =
[i][n]
Aharm
[i][1]
Aharm
n=2
50
2
i:phase(0;1;2)n:range(2to50)