Haefely 2830, Руководство пользователя, Страница: 19 / 124

Theory
11
Parallel equivalent diagram of a loss capacitance with vector
diagram
Loss factor (Dissipation Factor)
R C R
X
I
I P
C
C
R
 
= = = =


1
Q
tan
Power Factor
δ
tan 2
1
tan
cos
+
= = = =


S
P
I
I
PF
R
Q Reactive Powre
S Apparent Power
P Real Power
U
Test
applied test voltage
I
C
current through capacitance
I
R
current through resistance (insulating material)
I I
C
+ I
R
C ideal capacitance
R ideal resistance
Because P = Q • tan

, the losses which are proportional to tan

, will usually be given as a value
of tan

to express the quality of an insulation material. Therefore the angle

is described as loss
angle and tan

as loss factor.
5.2 Parallel and Series Equivalent Circuits
The measuring bridge measures and displays both - the parallel and/or series equivalent circuit
values.
The following formulas describe the calculation of the value conversion parallel
– series :
Parallel equivalent circuit
Parallel Equivalent
Circuit C
p
-R
p
Rp
Cp
=
 
1
 
tan * *
* measured values