GE D90 Plus Instruction Manual page 189

CHAPTER 7: PROTECTION
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
Middle Limit Angle
Range: 40 to 140° in steps of 1
Default: 90°
This setting defines the middle power swing detect characteristic. It is relevant only for
the three-step mode. A typical value would be close to the average of the outer and
inner limit angles. This setting applies to mho shapes only.
Inner Limit Angle
Range: 40 to 140° in steps of 1
Default: 60°
This setting defines the inner power swing detect characteristic. The inner characteristic
is used by the out-of-step tripping function: beyond the inner characteristic out-of-step
trip action is definite (the actual trip may be delayed as per the
Therefore, this angle must be selected in consideration to the power swing angle beyond
which the system becomes unstable and cannot recover.
Outer Right Blinder
Range: 0.10 to 500.00 ohms in steps of 0.01
Default: 10.00 ohms
This setting specifies the resistive reach of the right blinder for the outer mho and
quadrilateral characteristics. Set this value suitably high if no blinder is required for the
mho characteristic.
Outer Left Blinder
Range: 0.10 to 500.00 ohms in steps of 0.01
Default: 10.00 ohms
This setting specifies the resistive reach of the left blinder for the outer mho and
quadrilateral characteristics. Set this value suitably high if no blinder is required for the
mho characteristic.
Middle Right Blinder
Range: 0.10 to 500.00 ohms in steps of 0.01
Default: 10.00 ohms
This setting specifies the resistive reach of the right blinder for the middle mho and
quadrilateral characteristics. Set this value suitably high if no blinder is required for the
mho characteristic.
Middle Left Blinder
Range: 0.10 to 500.00 ohms in steps of 0.01
Default: 10.00 ohms
This setting specifies the resistive reach of the left blinder for the middle mho and
quadrilateral characteristics. Set this value suitably high if no blinder is required for the
mho characteristic.
Inner Right Blinder
Range: 0.10 to 500.00 ohms in steps of 0.01
Default: 10.00 ohms
This setting specifies the resistive reach of the right blinder for the inner mho and
quadrilateral characteristics. Set this value suitably high if no blinder is required for the
mho characteristic.
Inner Left Blinder
Range: 0.10 to 500.00 ohms in steps of 0.01
Default: 10.00 ohms
This setting specifies the resistive reach of the left blinder for the inner mho and
quadrilateral characteristics. Set this value suitably high if no blinder is required for the
mho characteristic.
GROUPED PROTECTION ELEMENTS
setting).
Trip Mode
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