Resistive Reach In Forward Direction - ABB Relion Technical Manual

1MRK 502 048-UUS A
7.1.6.1
7.1.6.2
Technical manual

Resistive reach in forward direction

To avoid load encroachment, the resistive reach is limited in forward direction by setting
the parameter RLdOutFw which is the outer resistive load boundary value while the inner
resistive boundary is calculated according to equation 36.
RLdInFw = kLdRFw·RLdOutFw
EQUATION1185 V2 EN
where:
kLdRFw is a settable multiplication factor less than 1
The slope of the load encroachment inner and outer boundary is defined by setting the
parameter LdAngle.
The load encroachment in the fourth quadrant uses the same settings as in the first
quadrant (same LdAngle and RLdOutFw and calculated value RLdInFw).
The quadrilateral characteristic in the first quadrant is tilted to get a better adaptation to the
distance measuring zones. The angle is the same as the line angle and derived from the
setting of the reactive reach inner boundary X1InFw and the line resistance for the inner
boundary R1LIn. The fault resistance coverage for the inner boundary is set by the
parameter R1FInFw.
From the setting parameter RLdOutFw and the calculated value RLdInFw a distance
between the inner and outer boundary, DFw, is calculated. This value is valid for R
direction in first and fourth quadrant and for X direction in first and second quadrant.
Resistive reach in reverse direction
To avoid load encroachment in reverse direction, the resistive reach is limited by setting
the parameter RLdOutRv for the outer boundary of the load encroachment zone. The
distance to the inner resistive load boundary RLdInRv is determined by using the setting
parameter kLdRRv in equation 37.
RLdInRv = kLdRRv·RLdOutRv
EQUATION1187 V2 EN
where:
kLdRRv is a settable multiplication factor less than 1
Section 7
Impedance protection
(Equation 36)
(Equation 37)
155