hager hw+ - 6.4 Measuring unbalances

84 6LE008146B
Measurement functions
6.4 Measuring unbalances
The sentinel Energy trip unit calculates in real-time (every second) current and voltage
unbalances.
Current unbalance is expressed as a % in relation to the average current.
Unbalanced current principle
Unbalanced current principle
Voltage unbalance is expressed as a % in relation to the arithmetic mean of the corresponding
voltage:
I
avg
=
I1 + I2 + I3
3
I
p
unbalance =
I
p
- I
avg
x100 with P = 1, 2, 3
I
avg
I1 IavgI2
I1 - Iavg
<0
I2 - Iavg
>0
U
avg
=
U12 + U23 + U31
3
U
pg
unbalance =
U
pg
- U
avg
x 100 with pg = 12, 23, 31
U
avg
U12
U23
Uavg
U12 - Uavg
<0
U23 - Uavg
>0