11
Electrical parameters of three-phase system are divided into three
symmetrical
components
which
are
positive-sequence
component,
negative-sequence component and zero-sequence component according to
symmetrical
component
method.
The
ratio
of
RMS
values
of
negative-sequence component and positive-sequence component is defined
as three-phase unbalance in the condition that power system is in normal
operation mode.
Unbalance(U)
4.4
▼
MENU
▲
218.8
0.001
000.4
000.2
Uunb
V
V
V
%
Uo
Neg. Seq.
Pos. Seq.
Unbalance-U
Positive sequence value=218.8V
Negative sequence value=0.4V
Zero sequence value=0.2V
Voltage unbalance value=0.001%
U n b a l a n c e ( I ) 4 . 5
▼
MENU
▲
3.999
0.001
0.005
0.002
A
A
A
%
Io
Neg. Seq.
Pos. Seq.
Iunb
Unbalance-I
Positive sequence value=3.999A
Negative sequence value=0.005A
Zero sequence value=0.002A
Current unbalance value=0.001%
Demand
Meter supports six independent demand recording channels which can
measure maximum demand value, present demand value and previous
demand value of three-phase current, total active power, total reactive power,
total apparent power.
