GE L90 Instruction Manual page 700

DISTANCE ELEMENTS
• Z — Left blinder characteristic impedance: Z
L
• K0 — Zero-sequence compensating factor: K0 = (
• K0M — Mutual zero-sequence compensating factor: K0M = 1/3 x
• Θ — Non-homogeneity angle setting (
10.3.3.2 Directional mho characteristic
The dynamic 100% memory polarized mho characteristic is achieved by checking the angle between
• AB phase element — (I
• BC phase element — (I
• CA phase element — (I
• A ground element — I
• B ground element — I
• C ground element — I
The limit angle of the comparator is adjustable, enabling the user to shape the characteristic as an mho or a lens as shown
in the figure. As explained in the Memory Polarization section, the memory-polarized mho characteristic has an excellent
directional integrity built-in.
10.3.3.3 Non-directional mho characteristics
The non-directional mho characteristic is achieved by checking the angle between
• AB phase element — (I
• BC phase element — (I
• CA phase element — (I
• A ground element — I
• B ground element — I
• C ground element — I
10.3.3.4 Mho reactance characteristic for directional applications
The reactance characteristic is achieved by checking the angle between
• AB phase element — (I
• BC phase element — (I
• CA phase element — (I
• A ground element — I
10
• B ground element — I
10-22
=
LFT BLD
L
Z0/Z1 MAG
NON-HOMOGEN ANG
– I ) × Z – (V – V ) and (V
A B A B
– I ) × Z – (V – V ) and (V
B C B C
– I ) × Z – (V – V ) and (V
C A C A
× Z + I_0 × K0 × Z + I × K0M × Z – V
A G
× Z + I_0 × K0 × Z + I × K0M × Z – V
B G
× Z + I_0 × K0 × Z + I × K0M × Z – V
C G
Figure 10-9: Mho (left) and lens (right) characteristics
– I ) × Z – (V – V ) and (V
A B A B
) × Z – (V
– I – V ) and (V
B C B C
– I ) × Z – (V – V ) and (V
C A C A
× Z + I_0 × K0 × Z + I × K0M × Z – V
A G
× Z + I_0 × K0 × Z + I × K0M × Z – V
B G
× Z + I_0 × K0 × Z + I × K0M × Z – V
C G
) × Z – (V
– I – V ) and (I
A B A B
– I ) × Z – (V – V ) and (I
B C B C
) × Z – (V
– I – V ) and (I
C A C A
× Z + I_0 × K0 × Z + I × K0M × Z – V
A G
× Z + I_0 × K0 × Z + I × K0M × Z – V
B G
× sin ( ) × 1∠ (
LFT BLD RCA LFT BLD RCA
∠ ) – 1
Z0/Z1 ANG
∠
Z0M/Z1 MAG Z0m/Z1 ANG
)
– V )_1M
A B
– V )_1M
B C
– V )_1M
C A
and V _1M
A A
and V _1M
B B
and V _1M
C C
– V ) – (I – I ) × Z
A B A B REV
) × Z
– V ) – (I – I
B C B C REV
– V ) – (I – I ) × Z
C A C A REV
× Z
and V – (I
A A A REV
and V – (I × Z
B B B REV
× Z
and V – (I
C C C REV
) × Z
– I
A B
– I ) × Z
B C
) × Z
– I
C A
and I_0 × Z
A
and I_0 × Z
B
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 10: THEORY OF OPERATION
+ 90°)
+ I_0 × K0 × Z × K0M × Z
+ I
REV G
+ I_0 × K0 × Z + I × K0M × Z
REV G
+ I_0 × K0 × Z × K0M × Z
+ I
REV G
)
REV
)
REV
)
REV