ABB RELION REX640, Техническое руководство, Страница: 942 / 1960

Non-directional Forward Reverse
Quadrilateral
Mho (circular)
Mho Dir line
Offset Dir line
Bullet (combi)
Pol. = polarization method affects (mho)zone shape
Imp zone shape
Pol. Pol.
Directional mode Znx
Pol. Pol.
Pol. Pol.
X
R
X X
X X
X X
X X
X X
R R
R R
R R
R R
R R
X
R
X
R
X
R
X
R
Figure 523: Possible combinations of Directional mode Znx and Zone characteristics
settings. Pol. here means that the shape of the characteristic is affected by the
selected polarization method of mho circle (Pol quantity zone = "Cross pol", "Pos.
seq. volt.", "Self pol")
The directional lines are polarized with the set polarizing quantity of all impedance
measuring elements. In addition, the memory voltage that is based on positive-
sequence voltage substitute for the measured voltage with any impedance
measurement element polarization if the corresponding voltage drops too low.
DSTPDIS has separate and independent measurement elements for each fault
loop in the distance protection zone. In addition to the full scheme design, the
separate measuring elements are used for general fault detection and faulted phase
selection.
DSTPDIS supports both fault detection dependent control of zone timers and zone-
dedicated phasewise timer control for maximum application flexibility.
The impedance measurement is always done the same way regardless of the zone
shape. The operation is based on the impedance mapping approach where the
fault loop impedance is first calculated and then compared to the zone boundaries.
If impedance is recognized within the operation zone, the corresponding operate
output is activated after the operate time has elapsed.
The impedance measurement is based on full-cycle DFT filtered current and voltage
phasors.
Protection functions 1MRS759142 F
942 REX640
Technical Manual