Load Encroachment - ABB REL650 Applications Manual

Section 6
Impedance protection
6.3.3.1
148
S max
=
ILoad
×
3 VLmn
EQUATION1615-ANSI V1 EN
where:
Smax is the maximal apparent power transfer during emergency conditions and
VLmn is the phase-to-phase voltage during the emergency conditions at the IED location.

Load encroachment

The load encroachment function has two setting parameters, RLd for the load resistance
and LdAngle for the inclination of the load sector (see figure 70).
LdAngle
LdAngle
RLdRv
ANSI10000192 V1 EN
Figure 70: Load encroachment characteristic
V
Zload = min
×
3 I
max
EQUATION1754-ANSI V1 EN
X
RLdFw
LdAngle
LdAngle
ANSI10000192_1_en.vsd
1MRK 506 334-UUS A
(Equation 67)
R
(Equation 68)
Application manual