Sec Rms Values For Voltage And Current; Voltage And Current Unbalance; Thd Calculation - AEMC PowerPad 3945-B User Manual

1 sec RMS Values for Voltage and Current

[]
Vrms i
=
NSS
[]
Urms
i
=
NSS
[]
Arms i
=
NSS

Voltage and Current Unbalance

1
=
V (VF[0] + a VF[1] + a
+
3
1
=
V (VF[0] + a
-
3
Vrms
-
Vunb =
Vrms
+

THD Calculation

50
∑
Vharm
n=2
Vthd[i] =
Vharm
i: phase (0; 1; 2)
94
NSS 1
1
−
∑ V
⋅
n 0
=
NSS 1
1
−
∑
U
⋅
n 0
=
1
1 NSS
−
∑
A
⋅
0
n
=
VF[2]) Direct voltage (complex notation a = e
2
VF[1] + a VF[2]) Reverse voltage
2
Arms
, Aunb =
Arms
2
[i][n]
, Uthd[i] =
[i][1]
n: range (2 to 50)
2
[][ ]
Single rms voltage i + 1 phase
i n
2
[][ ]
Compound rms voltage i + 1 phase
i n
2
[][ ]
Rms current i + 1 phase
i n
-
+
50
∑
Uharm [i][n]
n=2
Uharm [i][1]
Power Quality Analyzer Model 3945-B
50
∑
2
n=2
, Athd[i] =
Aharm
j 2π
)
3
2
Aharm [i][n]
[i][1]