Sel 411L - Figure 3.131 Quadrilateral Phase Distance Element Characteristic (TANGP = -10 Degrees); Figure 3.132 Network to Determine Homogeneity

P.3.193
Date Code 20151029 Protection Manual SEL-411L Relay
Protection Functions
Quadrilateral Phase Distance Elements
Figure 3.131 Quadrilateral Phase Distance Element Characteristic (TANGP = –10 degrees)
Quadrilateral Phase
Nonhomogeneous
Setting (TANGP)
Nonhomogeneous negative-sequence networks can cause distance elements to
underreach or overreach. Use the network in Figure 3.132 to determine
whether the negative-sequence network is homogeneous. Z
LEFT
is the total
impedance up to the fault (F) on the left-hand side, while Z
RIGHT
is the total
impedance up to the fault on the right-hand side.
Figure 3.132 Network to Determine Homogeneity
A network is homogeneous with respect to the particular fault location if
Equation 3.89 is satisfied.
Equation 3.89
Zone 3
TANGP = —10 degrees
Zone 2
Zone 1
Z1ANG
RP1
XP1
XP2
XP3
jX
—RP RP2 RP3
R
IF
F
IF
Z
RIGHTZLEFT
Z1S m • Z1L (1 — m) • Z1L Z1R
SR
X
LEFT
R
LEFT
----------------
X
RIGHT
R
RIGHT
--------------------=