ABB RES670 Technical Manual page 168

Section 7
Impedance protection
162
of-step characteristic which corresponds to the rotor (power) angle of 90 degrees).
Figure 45 illustrates construction of the lens characteristic for a power system.
0.6
0.4
X-line -
-
determined
-
®
by the
^ ^ ^ ^
-
0.2
setting
-
ReachZ1
-
- -
0 Zone 1
-
-
-
-
-0.2
-
®
limit-of-reach
-
circle depends on
-0.4
the position of the
points SE and RE
-0.6
-0.8 -0.6 -0.4
ANSI10000112 V1 EN-US
Figure 45: Construction of the lens characteristic for a power system
ReverseZ(ReverseR, ReverseX)
Zgen(Rgen, Xgen)
Generator Generator
13.8 kV 13.8 kV
d
13.8 kV 13.8 kV
SE SE
Out-Of-Step
REG REG
protection
OOSPPAM
ANSI10000113 V1 EN-US
Figure 46: Example of an actual power system
To be able to automatically construct the lens characteristic for a system shown in
Figure 46, the actual power system must be modeled as a two-machine equivalent
X
-
- RE -
- -
- -
- - -
- -
- - - -
- - -
- - - -
- -
- - - -
- -
Ze
- -
- - -
Zone 2
- - - -
- - - -
- -
- -
- -
Zline
- -
- -
- -
^ ^ ^ ^
- -
^ ^ ^ ^
- -
^ ^ ^ ^
- -
Ztr
- -
- -
- -
relay
- -
120°
- -
- -
- - ¬
Z-line
- -
- -
- -
Zgen
- -
- -
- -
- -
¬
- - - -
- -
-
- -
- -
- -
-
- - -
- -
-
- - -
- -
-
- - -
- -
- -
- -
- -
-
SE
by the setting Pickup Angle
-0.2 0 0.2
Real part (R) of Z in Ohms
ForwardZ(ForwardR, ForwardX)
Ztr(Rtr, Xtr) Zline(Rline, Xline)
Transformer
13.8 / 220 kV
Y
ReverseR = Rg ReverseR = Rg
ReverseX = Xd' ReverseX = Xd'
All impedances must be referred to the generator voltage 13.8 kV
1MRK 511 408-UUS A
Position of the OOS
relay is the origin of
-
the R - X plane
-
-
-
-
-
-
- -
-
- -
-
- -
- -
-
^ ^
- -
R
- -
- -
- -
-
- -
-
- -
Z(R,X)
-
-
-
-
Lens is the locus
-
of constant rotor (power)
-
-
angle, e.g. 120°.
-
Lens' width determined
0.4 0.6 0.8 1
ANSI10000112-1-en.vsd
Zeq(Req, Xeq)
Infinite power Infinite power
Power line Power line System
220 kV 220 kV equivalent
ForwardR = Rtr + Rline + Req ForwardR = Rtr + Rline + Req
For wardX = Xtr + Xline + Xeq = Xtr + Xline + Xeq
ANSI10000113-1-en.vsd
Phasor measurement unit RES670 2.2 ANSI
system system
RE RE
Technical manual