Functions
2.3 Directional Overcurrent Protection 67, 67N
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
111
Direction Characteristic
The direction characteristic, i.e. the position of the ranges „forward“ and „reverse“ is set for the phase directional
elements under address
1519
ROTATION ANGLE
and for the ground directional element under address
1619
ROTATION ANGLE
. The short-circuit angle is generally inductive in a range of 30° to 60°. This means that
usually the default settings of +45° for the phase directional elements and -45° for the ground directional
element can be maintained for the adjustment of the reference voltage, as they guarantee a safe direction
result.
Nevertheless, the following contains some setting examples for special applications (Table 2-8). The following
must be observed: With the phase directional elements, the reference voltage (fault-free voltage) for phase-
ground-faults is vertical on the short-circuit voltage. For this reason, the resulting setting of the angle of rotation
is (see also Section 2.3.8):
With the ground directional element, the reference voltage is the short-circuit voltage itself. The resulting setting
of the angle of rotation is then:
It should also be noted for phase directional elements that with phase-to-phase faults, the reference voltage is
rotated between 0° (remote fault) and 30° (close-up fault) depending on the collapse of the faulty voltage. This
can be taken into account with a mean value of 15°:
Table 2-8
Setting examples
1)
Power flow direction
2)
With the assumption that these are cable lines
Ref. volt. angle of rotation = 90 -
ϕ
k
Phase directional element (phase-to-earth fault).
Ref. volt. angle of rotation = -
ϕ
k
Directional ground element (phase-to-earth fault).
Ref. volt. angle of rotation = 90 -
ϕ
k
-15°
Phase directional element (phase-to-phase fault).
Application
ϕ
sc
typical
Setting
Directional Phase
Element
1519 ROTATION
ANGLE
Setting
Directional Ground
Element
1619 ROTATION
ANGLE
60°
Range 30°..0.0°
→
15°
–60°
30°
Range 60°...30°
→
45°
–30°
30°
Range 60°...30°
→
45°
–30°
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