ABB Relion 670 series - Directional Impedance Element for Quadrilateral Characteristics; Load Impedance Limitation, with Phase Selection with Load Encroachment, Quadrilateral Characteristic Function Activated; Setting of Minimum Operating Currents

Set the fault resistance coverage RFRwPP and RFRwPG to the same value as in forward
direction, if that suits the application. All this is applicable for all measuring zones when
no Power swing detection function ZMRPSB (78) is activated in the IED. Use an
additional safety margin of approximately 20% in cases when a ZMRPSB (78) function
is activated in the IED, refer to the description of Power swing detection function
ZMRPSB (78).
8.3.3.8 Load impedance limitation, with Phase selection with load encroachment,
quadrilateral characteristic function activated
The parameters for shaping of the load encroachment characteristic are found in the
description of Phase selection with load encroachment, quadrilateral characteristic
function (FDPSPDIS, 21).
8.3.3.9 Setting of minimum operating currents
The operation of Distance protection zone, quadrilateral characteristic (ZMQPDIS, 21)
can be blocked if the magnitude of the currents is below the set value of the parameter
IMinPUPP and IMinPUPG.
The default setting of IMinPUPP and IMinPUPG is 20% of IBase where IBase is the
chosen current for the analogue input channels. The value has been proven in practice to
be suitable in most of the applications. However, there might be applications where it is
necessary to increase the sensitivity by reducing the minimum operating current down to
10% of IBase. This happens especially in cases, when the IED serves as a remote back-up
protection on series of very long transmission lines.
Setting IMinOpIR blocks the phase-to-ground loop if 3I
0
<IMinOpIR. The default setting
of IMinOpIR is 5% of IBase.
The minimum operating fault current is automatically reduced to 75% of its set value, if
the distance protection zone has been set for the operation in reverse direction.
8.3.3.10 Directional impedance element for quadrilateral characteristics
The evaluation of the directionality takes place in Directional impedance quadrilateral
function ZDRDIR (21D). Equation
149 and equation 150 are used to classify that the fault
is in forward direction for phase-to-ground fault and phase-to-phase fault.
1 1
1
0.8 1 0.2 1
arg Re
L L M
L
V V
ArgDir ArgNeg s
I
× + ×
- < <
EQUATION1552 V2 EN (Equation 149)
Section 8 1MRK 506 369-UUS -
Impedance protection
248 Line distance protection REL670 2.2 ANSI
Application manual