Siemens siprotec SJ62 User Manual page 106

Direction Charac-
teristic
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
The direction characteristic, i.e. the position of the ranges „forward" and „backward" 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°. I.e., usually the default set-
tings 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 guar-
antee a safe direction result.
Nevertheless, the following contains some setting examples for special applications
(Table 2-7). 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):
Angle of rotation of ref. volt. = 90 - ϕ
With the ground directional element, the reference voltage is the short-circuit voltage
itself. The resulting setting of the angle of rotation is then:
Angle of rotation of ref. volt. = -ϕ
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) de-
pending on the collapse of the faulty voltage. This can be taken into account with a
mean value of 15°:
Angle of rotation of ref. volt. = 90 - ϕ
2.3 Directional Overcurrent Protection 67, 67N
phase directional element
sc
(phase-ground fault)
ground directional element
sc
(phase-ground fault)
-15° phase directional element
sc
(phase-to-phase fault).
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