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104
FUNCTION CHARACTERISTICS
One adjustable operation threshold, (
U
E3H
>) with definite time adjustable delay (
t
UE3H
>).
The elements are enabled in the 20 Hz ... 70 frequency range.
U
U
E3H
>
t
t
UE3H
>
TRIP
General operation time characteristic curve for the third harmonic overvoltage element - 59H
3rd-har-line.ai
U
E3H
prima
del guasto
27H
59N
59H
59N
100%
100%
0
0
Evolution of fundamental and third harmonic components of residual voltage
along the stator winding, measured by means of the line side VT
third harmonic component
without fault
fundamental component of the
residual voltage without fault
3rd harmonic maximum
voltage threshold
U
E3H
>
third harmonic component
in the presence of earth fault
in the star center
third harmonic component
in the presence of earth fault inlimit
point detectable by 59H
third harmonic component
with earth fault on terminals
fundamental component of the
residual voltage with earth fault
along the winding
59N threshold,
U
E
> or
U
E
>>
XMR-D EQUIPMENT MANUAL
Ed. 2.9 - 02/2021