GE L90 Instruction Manual page 546

9.3 DISTANCE ELEMENTS
X
MHO CHARACTERISTIC
c) NON-DIRECTIONAL MHO CHARACTERISTIC
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:
 Z + I_0  K0  Z + I
I
A
• B ground element:
 Z + I_0  K0  Z + I
I
B
• C ground element:
 Z + I_0  K0  Z + I
I
C
d) 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
• B ground element: I
• C ground element: I
If the mho characteristic is selected, the limit angle of the comparator is adjustable concurrently with the limit angle of the
mho characteristic, resulting in a tent shape complementing the lens characteristic being effectively applied.
e) QUADRILATERAL REACTANCE CHARACTERISTIC FOR DIRECTIONAL APPLICATIONS
The quadrilateral reactance characteristic is achieved by checking the angle between:
• AB phase element: (I
9
• BC phase element: (I
• CA phase element: (I
• A ground element: I
• B ground element: I
• C ground element: I
9-22
Reach setting
Comparator angle setting= 90
R
Figure 9–9: MHO AND LENS CHARACTERISTICS
)  Z – (V
– I – V ) and
A B A B
)  Z – (V
– I – V ) and
B C B C
)  Z – (V
– I – V ) and
C A C A
 K0M  Z – V
and
G A
 K0M  Z – V
and
G B
 K0M  Z – V
and
G C
)  Z – (V
– I – V ) and
A B A B
)  Z – (V
– I – V ) and
B C B C
)  Z – (V
– I – V ) and
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
A B A B
)  Z – (V
– I – V ) and
B C B C
)  Z – (V
– I – V ) and
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
L90 Line Current Differential System
X
837715A2.CDR
)  Z
(V – V ) – (I – I
A B A B REV
)  Z
(V – V ) – (I – I
B C B C REV
)  Z
(V – V ) – (I – I
C A C A REV
 Z + I_0  K0  Z
V – (I
A A REV
 Z + I_0  K0  Z
V – (I
B B REV
 Z + I_0  K0  Z
V – (I
C C REV
)  Z.
(I – I
A B
)  Z.
(I – I
B C
)  Z.
(I – I
C A
I_0  Z.
and
A
I_0  Z.
and
B
I_0  Z.
and
C
)  Z.
(I – I
A B
)  Z.
(I – I
B C
)  Z.
(I – I
C A
(j  I_0 or j  I_2A)  e
and
A
(j  I_0 or j  I_2B)  e
and
B
(j  I_0 or j  I_2C)  e
and
C
9 THEORY OF OPERATION
Reach setting
Comparator angle setting < 90
R
LENS CHARACTERISTIC
 K0M  Z
+ I )
REV G REV
 K0M  Z
+ I )
REV G REV
 K0M  Z
+ I )
REV G REV
j
.
j
.
j
.
GE Multilin
837714A2.CDR