These three are called positive sequence, negative and zero sequence systems.
For a perfectly balanced system both negative and zero sequence systems would
be absent.
The screen displays: +V1, -V2, N.
I VECTOR: (The current vector)
To look at the positive component, negative
component and zero component.
The Screen displays: +I1, -I2, N.
7.5: Energy
Select Menu
: Move the highlighted feature up or
down by pressing the arrows marked
to the
“Energy” line.
Energy
: Press the return key
this will take you to
the Energy screen (only one screen).
The screen displays: Import and Export Kwh, Kvarh
and Import Kvah.
8
K FACTOR: (Current K Factor)
K-factor is a weighting of the harmonic load
currents according to their effects on
transformer heating, as derived from ANSI/IEEE
C57.110. A K-factor of 1.0 indicates a linear load
(no harmonics). The higher the K-factor, the
greater the harmonic heating effects.
The screen displays: I1, I2, I3.
UNBAL FACTOR: (Unbalance Factor)
To look at the current and voltage unbalance
factor. In a 3-phase distribution, if the current or
voltage RMS are not the same or the difference
between a 3 phase angle is not 120 degrees, we
call the phase voltages or current ‘unbalance’.
The unbalance voltage or current of 3-phase can
be divided into positive component, negative
component and zero component.
The screen displays:
Vu f %
(Voltage unbalanced factor),
Iuf %
(Current unbalanced factor)
V PEAK: (The Peak Voltage)
Peak voltage is the highest level of volts from an
alternating current. For example, in the UK the
mains supply to a house is 230RMS. 230 volts is
the average (simplified) you will get from the
AC supply. But in reality the AC wave switches
between -320 and 320 volts. So 320 is the
peak voltage.
To find out the peak voltage of an alternating
current you must multiply the RMS voltage by
root2 or 0.707 (this works only when the AC
signal is a sine wave).
The screen displays: V1,V2,V3.
V VECTOR: (The Voltage Vector)
Widely-used in European standards, the first
definition originates from the theory of
Symmetrical Components which mathematically
breaks down an unbalanced system into three
balanced systems as shown.
10
11
0 8- 14- 20 0 9
17 56 57
002.6
002.2
UNBAL FACTOR 04
Vuf
Iuf
%
%
0 8- 14- 20 0 9
17 56 57
335.5
334.8
331.4
V PEAK 05
L1
L2
L3
0 8- 14- 20 0 9
17 56 57
230.2
059.6
030.0
V VECTOR 06
+
-
N
V
a0
V
b0
V
c0
V
a2
V
b2
V
c2
V
a1
V
b1
V
c1
A
a0
A
b0
A
c0
A
a2
A
b2
A
c2
A
a1
A
b1
A
c1
positive sequence
negative sequence
zero sequence
positive sequence
negative sequence
zero sequence
0 8- 14- 20 0 9
17 56 57
0.094
0.002
0.000
I VECTOR 07
+
-
N
A
A
A
+kwh
+kvarh
kvah
-kwh
-kvarh
