Table of Contents
Advertisement
Technical Data
4.9 Earth Fault Protection in Earthed Systems (optional)
Determination of Direction
Each zone can be set to operate in forward or reverse direction, non-directional or ineffective.
Direction measurement
Limit values
Displacement voltage 3U
Starpoint current of a power transformer
I
>
Y
Negative sequence current 3I
Negative sequence voltage 3U
"Forward" angle
Capacitive alpha
Inductive beta
Tolerances pickup values
Tolerance forward angle
Re-orientation time after direction change
602
>
0
for I
= 1 A
N
for I
= 5 A
N
>
for I
= 1 A
2
N
for I
= 5 A
N
>
2
With I
(= 3 I
) and 3 U
and I
E
0
0
with I
(= 3 I
) and 3 U
and I
E
0
0
With I
(= 3 I
) and I
(starpoint current of a power transformer)
E
0
Y
With I
and U
(negative sequence quantities)
2
2
With zero-sequence power
0.5 V to 10.0 V
0.05 A to 1.00 A
0.25 A to 5.00 A
0.05 A to 1.00 A
0.25 A to 5.00 A
0.5 V to 10.0 V
0° to 360°
0° to 360°
10 % of set value or 5 % of nominal current or 0.5 V
5°
Approx. 30 ms
C53000-G1176-C169-5, Release date 02.2011
or I
and U
Y
2
2
Y
Increments 0.1 V
Increments 0.01 A
Increments 0.01 A
Increments 0.1 V
Increments 1°
Increments 1°
SIPROTEC, 7SD5, Manual
Advertisement
Table of Contents
