Hioki 3197 - Terminology

Appendix 9 Definitions
A 18
Terminology
K Factor Also called the multiplication factor, the K factor expresses the power loss
caused by harmonic currents in a transformer.
The formula for calculating K factor (KF) is:
k: Order of harmonic
Ik: Percentage of harmonic current relative to the fundamental current [%]
Higher-order harmonic currents have a greater influence on the K factor than
do l
ower-order harmonic currents.
The K factor is measured while the transformer is subjected to the maximum
c
ircuit load.
If the measured K factor is larger than the multiplication ratio of the transformer
bei
ng used, the transformer should be replaced with one having a higher K
factor, or the load on the transformer must be reduced.
When replacing a transformer, the replacement should have a K factor one
ra
nk higher than the K factor measured with the transformer being replaced.
Harmonic Phase
An
gle and Har-
monic Phase Dif-
ference
The harmonic voltage phase angle and harmonic current phase angle are
bas
ed upon the phase of the fundamental component of the PLL source
(referenced to the PLL input, which is selected from U1 in this instrument).
The phase difference between each harmonic component and the
fun
damental component is expressed as an angle (º), with a positive sign
signifying lagging phase (LAG) and a negative sign signifying leading phase
(LEAD).
The harmonic voltage-current phase difference expresses the difference
bet
ween the phase of each harmonic order voltage component and the phase
of each harmonic order current component for each channel, as an angle (º).
The sum is the total power factor of each harmonic order (calculated from the
tota
l harmonic power and total harmonic reactive power) expressed as an
angle (°). When the harmonic voltage-current phase difference is between -90°
and +90°, the power of that harmonic order is flowing toward the load (inflow).
Whe
n it is between +90° and +180° or between -90° and -180°, the power of
that harmonic order is flowing away from the load (outflow).
KF
k
2
I
k
×
2


k
1=
50

I
k
2
k
1=
50

----------------------------------
=
0°
90°
-90°
±
180°
Harmonic Phase Angle
Voltage-Current Phase Difference
Outflow
Inflow
LEAD (Lead)
LAG (Lag)
Voltage-Current
Phase Angle