Arteche smART P500, Instruction Manual

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1BPROTECTION FUNCTIONS
PROTECTION, CONTROL AND METERING FUNCTIONS
2.1.4.2. CONFIGURATION
The directionality configuration is independently set for each group using the option
“Directional overcurrent (67/67N/67NS)” given in the proART software. It is possible
to enable the directionality (forward, backward or bidirectional). Independent settings
can be used for polarization voltage and maximum torque angle for phase to ground,
phase to phase and neutral faults.
The settings angle may vary from 0º to 90º.
For backward faults the same settings are used, but applied like a mirror, rotated
180º Figure 2-10.
Figure 2-10 Directionality criterion
Depending on the type of fault (phase to ground, phase to phase, neutral) a choice
can be made between several polarization voltages, (fault voltage, quadrature
voltage and zero, positive or negative-sequence voltages)
When a fault occurs its type is determined from the phases with a pickup indication.
The directionality determining algorithm selects the correct voltage and calculates the
angle between the current and voltage phasors. If the angle falls in the forward zone,
the protection will work in that direction; but if the angle falls in the backward zone, it
will work with the settings for that zone.
The relay doesn’t operate if the angle between current and voltage falls out of the
tripping zones.