Fast Distance Algorithm - GE L90 Instruction Manual

DISTANCE ELEMENTS
Table 10-4: Directional quadrilateral ground distance functions
Characteristic
Reactance
Directional
Directional
Right Blinder
Left Blinder
Fault-type
Zero-sequence
Table 10-5: Non-directional mho phase distance functions
Characteristic
Offset mho
Fault type
Table 10-6: Non-directional mho ground distance functions
Characteristic
Offset mho
Fault-type
Table 10-7: Non-directional quadrilateral phase distance functions
Characteristic
Forward Reactance
Reverse Reactance
Right Blinder
Left Blinder
Fault type
Table 10-8: Non-directional quadrilateral ground distance functions
Characteristic
Forward Reactance
Reverse Reactance
Right Blinder
Left Blinder
Fault-type

10.3.4 Fast distance algorithm

In order to improve operating speed of the phase and ground distance zone 1 and zone 2 elements under CVT transient
conditions for high SIRs up to 60, a fast distance algorithm is implemented in the relay. This algorithm uses a weighted
average digital filtering technique and runs in parallel with a regular distance algorithm, which uses a fixed digital CVT
filtering technique. The fast distance algorithm applies the same comparators as a regular distance algorithm.
10
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Comparator inputs
I × Z – V j × I_0 × e
jΘ
× e
I_0 × Z V_1M
D
I_2 × Z V_1M
D
I × Z – V I × Z
R R
I × Z – V I × Z
L L
I_0 I_2
I_0 × Z –V_0
D
Comparator inputs
I × Z – V V-I × Z
REV
NOT SLG See the Fault Type Characteristic section
Comparator inputs
I × Z – V V-I × Z
REV
I_0 I_2
Comparator inputs
I × Z – V I × Z
I × Z – V I × Z
REV REV
I × Z – V I × Z
R R
I × Z – V I × Z
L L
NOT SLG See the Fault Type Characteristic section
Comparator inputs
I × Z – V j × I_0 × e
jΘ
× e
I × Z – V –j × I_0 × e
REV
jΘ
I_2 × e
I × Z – V I × Z
R R
I × Z – V I × Z
L L
I_0 I_2
Limit angle
jΘ
or j × I_2 COMP LIMIT
DIR COMP LIMIT
DIR COMP LIMIT (removed when 3I_0 > OC SUPV and I_2 < CUTOFF)
90°
90°
50° (removed during open pole conditions or when 3I_0 > OC SUPV
and I_2 < CUTOFF)
90° (zones and higher only; removed for zones 2 and higher during
open pole conditions)
Limit angle
COMP LIMIT
50° (removed during open pole conditions or when 3I_0 > OC
SUPV and I_2 < CUTOFF)
Limit angle
jΘ
or j × I_2 COMP LIMIT
jΘ
or –j × COMP LIMIT
90°
90°
50° (removed during open pole conditions or when 3I_0 > OC
SUPV and I_2 < CUTOFF)
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 10: THEORY OF OPERATION
Limit angle
COMP LIMIT
Removed during open pole conditions
Limit angle
COMP LIMIT
COMP LIMIT
90°
90°
Removed during open pole conditions