ABB Relion 650 Series Technical Manual page 101

1MRK 506 326-UUS B
IEC08000437 V1 EN-US
Figure 49: Rotation of load characteristic for a fault between two phases
There is a gain in selectivity by using the same measurement as for the quadrilateral characteristic
since not all phase-to-phase loops will be fully affected by a fault between two phases. It should
also provide better fault resistive coverage in quadrant one.
5.2.6.5 Minimum operate currents
The operation of the Phase selection with load encroachment function (FDPSPDIS, 21) is blocked if
the magnitude of input currents falls below certain threshold values.
The phase-to-ground loop n is blocked if In<
phase n (A or B or C).
The phase-to-phase loop mn is blocked if (2·In<
5.2.6.6 Simplified logic diagrams
Figure 50
operating conditions. Consider only the corresponding part of measuring and logic circuits, when
only a phase-to-ground or phase-to-phase measurement is available within the IED.
Line distance protection REL650
Technical manual
X
presents schematically the creation of the phase-to-phase and phase-to-ground
© Copyright 2011 ABB Power Grids. All rights reserved
R
IEC08000437.vsd
IMinPUPG , where In is the RMS value of the current in
IMinPUPP ).
Section 5
Impedance protection
M13140-102 v3
M13140-107 v5
95