Sec Rms Values For Voltage And Current; Voltage And Current Unbalance; Thd Calculation (No Neutral) - AEMC 8335 User Manual

1 sec RMS Values for Voltage and Current

[]
Vrms
i
=
NSS
[]
Urms i
=
NSS
[]
Arms i
=
NSS
NSS: number of samples in a second (multiple of NSC)

Voltage and Current Unbalance

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

THD Calculation (no neutral)

50
∑
Vharm
n=2
Vthd[i] =
Vharm
i: phase (0; 1; 2)
94
NSS 1
1
−
∑
V
⋅
n 0
=
1
1 NSS
−
∑ U
⋅
0
n
=
1 NSS 1
−
∑ A
⋅
n 0
=
2
VFrms[1] + a VFrms[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
VFrms[2]) Direct voltage (complex notation a = e
-
+
50
∑
[i][n]
Uharm
n=2
[i][1]
Uharm
Power Quality Analyzer Model 8335
50
∑
2
n=2
, Athd[i] =
Aharm
j 2π
)
3
2
[i][n]
Aharm
[i][1]