80
Power Quality Analyzer Model 3945
C
HAPTER
8
A
PPENDIX
8.1 Mathematical Formulas for Various Parameters
8.1.1 Half-period Voltage and Current RMS Values
[]
[][ ]
2
Vdem
:
2
∑
⋅
=
Next Zero
Zero
n
n
i
V
NSC
i
Single rms voltage half-period i + 1 phase
[]
[][ ]
2
Udem
Compound rms voltage half-period i + 1 phase
:
2
∑
⋅
=
Next Zero
Zero
n
n
i
U
NSC
i
[]
[][ ]
2
Adem
:
2
∑
⋅
=
Next Zero
Zero
n
n
i
A
NSC
i
Rms current half-period i + 1 phase
NSC: number of samples by cycle
n: sample (0; 255)
i: phase (0; 1; 2)
8.1.2 MIN / MAX Values for Voltage and Current
Vmax[
i
] = max (Vdem[
i
]), Vmin[
i
] = min (Vdem[
i
]), Vavg=1/6000
Σ
Vdem[
i
]
Umax[
i
] = max (Udem[
i
]), Umin[
i
] = min (Udem[
i
]), Aavg=1/6000
Σ
Adem[
i
]
Amax[
i
] = max (Adem[
i
]), Amin[
i
] = min (Adem[
i
]) (Avg calculation on 1s)
8.1.3 Peak Values for Voltage and Current
Vpp[
i
] = max (V[
i
]][n]), Vpm[
i
] = min (V[
i
][n]), n
∈
[0..NECHPER-1]
Upp[
i
] = max (U[
i
]][n]), Upm[
i
] = min (U[
i
][n]), n
∈
[0..NECHPER-1]
App[
i
] = max (A[
i
][n]), Apm[
i
] = min (V[
i
][n]), n
∈
[0..NECHPER-1]
