ABB RELION RET670 - Load Impedance Limitation, with Phase Selection with Load Encroachment, Quadrilateral Characteristic Function Activated

RFFwPP Z
R
X
load
≤ ⋅ ⋅ ∂ − ⋅ ∂






1 6
1
1
. cos sin
min
IEC13000276 V1 EN-US (Equation 153)
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
SEMOD55087-138 v5
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
SEMOD55087-141 v5
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
M16923-139 v6
The evaluation of the directionality takes place in Directional impedance quadrilateral
function ZDRDIR (21D). Equation
154 and equation 155 are used to classify that the
fault is in forward direction for phase-to-ground fault and phase-to-phase fault.
Section 8 1MRK 504 163-UUS A
Impedance protection
282 Transformer protection RET670 2.2 ANSI
Application manual