Schweitzer Engineering Laboratories SEL-311L Instruction Manual page 164

D C
IRECTIONAL ONTROL FOR
E
LEMENTS
The directional control for phase distance and negative-sequence overcurrent elements is
configured by making directional control setting E32. Setting E32 and other directional control
settings are described in the following subsection Directional Control Settings.
Negative-sequence voltage-polarized and positive-sequence voltage-polarized directional
elements control the phase distance elements. The negative-sequence voltage-polarized
directional element operates for unbalanced faults, while the positive-sequence voltage-polarized
directional element operates for three-phase faults. Figure 4.13 gives an overview of how the
negative-sequence voltage-polarized and positive-sequence voltage-polarized directional
elements are enabled and routed.
Figure 4.13: General Logic Flow of Directional Control for Negative-Sequence Phase
Overcurrent and Phase Distance Elements
Internal Enables
Refer to Figure 4.6 and Figure 4.13.
The Relay Word bit 32QE enables the negative-sequence voltage-polarized directional element.
The settings involved with 32QE in Figure 4.6 (e.g., setting a2) are explained in a following
subsection Directional Control Settings.
4-18
P D
HASE ISTANCE AND
Loss-of-Potential, CCVT Transient Detection,
Load-Encroachment, and Directional Element Logic
SEL-311L Instruction Manual
N -S
EGATIVE EQUENCE
Date Code 20010625