Fluke 6105A - Page 40

6100B/6105A
Users Manual
1-26
WattsPu 1866.03266.74610250)(
6
1
=××=
−
Accuracy contribution for the 3rd harmonic
ppm
V
V
ppmVu 415
15
100044.0
122)(
6
3
=
×
+=
ppm
A
A
ppmIu 534
7.0
1000024.0
191)(
6
3
=
×
+=
ppmephaseu 28361
)61cos(
)009.061cos(
1)(
3
=×
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
+
−=
Combined accuracy for the 3rd harmonic components
ppmPu 733283534415)(
222
3
=++=
Power in the 3rd harmonic components:
WattsIVP 0905.5484810.07.015cos
3333
=××=Φ=
so:
WattsPu 003732.00905.510733)(
6
3
=××=
−
Total power
4171.7510905.53266.746
31
=+=+= PPP Watts
From:
∑
=
=
N
i
iic
PucPu
1
)(.)(
WattsPu
c
1854.0003731.0
4171.751
0905.5
1866.0
4171.751
3266.746
)( =×+×=
WattsAccuracyPower 1854.04171.751 ±=
Reactive Power Calculation Methods
Under pure sinusoidal conditions, Apparent Power (S), Power (P) and Reactive power (Q) are related by:
S
2
= P
2
+ Q
2
. This relationship is known as the Power Triangle. When either the voltage or current waveform is not
sinusoidal, the power triangle is not satisfied by this equation. This has lead to various attempts to better define
Reactive Power (Q) but no single definition has been agreed. The difficulty is that Q is used for a number of different
calculations including transmission line efficiency and voltage line drop. The 6100B allows users to select the
definition that best meets their needs. The following methods are supported:
Budeanu Fryze
Kusters and Moore Shepherd and Zakikhani
Sharon / Czarnecki IEEE working group
Because of the complexity of the subject, definition of the methods listed is beyond the scope of this document.
References to relevant documentation are provided at the reference
Reactive Power
For reactive Power (Q) calculate u φ(Q) from
)
)sin(
))(sin(
1()(
Φ
+Φ
−=
φ u
Qu
The method used for calculation of reactive power in non-sinusoidal conditions is user selectable.