Appendix – theoretical outline – HT instruments HT9022 User Manual
Page 53
HT9022
EN - 51
9. APPENDIX – THEORETICAL OUTLINE
9.1.
CALCULATION OF POWERS IN “AC 1P” MODE
The instrument measures the values of Rms Voltage and Rms Current and calculates the
average Power values for each period. The formulas for power calculation are:
∑
=
Ч
Ч
=
N
i
i
i
i
v
N
P
1
1
∑
∑
=
=
Ч
Ч
Ч
=
N
i
i
N
i
i
i
N
v
N
S
1
2
1
2
1
1
2
2
P
S
Q
−
=
S
P
Pf
=
where:
N = number of samples in the period
9.2.
CALCULATION OF POWERS IN “AC 3P” MODE
The instrument measures the values of Rms Voltage and Rms Current and calculates the
average Power values for each period. The formulas for power calculation are:
∑
=
Ч
Ч
Ч
=
N
i
i
i
i
v
N
Q
1
1
3
∑
∑
=
=
Ч
Ч
Ч
Ч
=
N
i
i
N
i
i
i
N
v
N
S
1
2
1
2
1
1
3
2
2
Q
S
P
−
=
S
P
Pf
=
where:
N = number of samples in the period
9.3.
CALCULATION OF POWERS IN “DC” MODE
The instrument measures the values of Avg Voltage and Avg Current and calculates the
average Power value for each period. The formula for power calculation is:
⎟
⎠
⎞
⎜
⎝
⎛
Ч
Ч
⎟
⎠
⎞
⎜
⎝
⎛
Ч
=
∑
∑
=
=
N
i
i
N
i
i
i
N
v
N
P
1
1
1
1