ABB Relion 670 Series RES670, Technical Manual

Page: 168 / 888

corresponds to the rotor (power) angle of 90 degrees). Figure 44 illustrates construction of
the lens characteristic for a power system.
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Real part (R) of Z in Ohms
Im
a
g
in
a
ry
p
a
rt
(
X
)
o
f Z
in
O
h
m
s
^ ^ ^ ^ ^ ^ ^
^ ^ ^ ^ ^ ^ ^
^ ^ ^ ^
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Ztr
Ze
Zgen
SE
RE
Z(R,X)
R
Zline
Zone 2
relay
¬
Z-line
120°
¬
Lens is the locus
of constant rotor (power)
angle, e.g. 120°.
Lens' width determined
by the setting Pickup Angle
X
Position of the OOS
relay is the origin of
the R - X plane
Zone 1
limit-of-reach
®
circle depends on
the position of the
points SE and RE
X-line
determined
by the
®
setting
ReachZ1
ANSI10000112-1-en.vsd
ANSI10000112 V1 EN
Figure 44: Construction of the lens characteristic for a power system
ANSI10000113-1-en.vsd
d
Y
Generator
13.8 kV
13.8 kV
Power line
220 kV
Infinite power
system
Out-Of-Step
protection
OOSPPAM
13.8 / 220 kV
REG
ForwardZ(ForwardR, ForwardX)
ReverseR = Rg ForwardR = Rtr + Rline + Req
ReverseX = Xd’ ForwardX = Xtr + Xline + Xeq
All impedances must be referred to the generator voltage 13.8 kV
SE RE
Generator
13.8 kV
13.8 kV
Power line
220 kV
Infinite power
system
Transformer
System
equivalent
REG
Zgen(Rgen, Xgen) Ztr(Rtr, Xtr) Zline(Rline, Xline) Zeq(Req, Xeq)
ReverseZ(ReverseR, ReverseX)
ReverseR = Rg ForwardR = Rtr + Rline + Req
ReverseX = Xd’ = Xtr + Xline + Xeq
SE RE
ANSI10000113 V1 EN
Figure 45: Example of an actual power system
Section 7
1MRK 511 365-UUS A
Impedance protection
162 Phasor measurement unit RES670 2.1 ANSI
Technical manual