Toshiba GRL100-701B Instruction Manual page 56

V a = (I a − I 0 )Z 1 + I 0 × Z 0 + I om × Z om
where,
V a : Phase "a" voltage
I a : Phase "a" current
I 0 : Zero-sequence current of the protected line
I 0m : Zero-sequence current of the parallel line
Z 1 : Positive-sequence impedance (Z 1 = R 1 + jX 1 )
Z 0 : Zero-sequence impedance (Z 0 = R 0 + jX 0 )
Z 0m : Zero-sequence mutual impedance (Z om = R om + jX om )
Equation (1) can be written as follows:
V a = (R 1 + jX 1 )I a + {(R 0 − R 1 ) + j(X 0 − X 1 )}I 0 + (R om + jX om )I om
−
R 0
= R 1 (I a +
R 1
In the GRL100, the voltage is compensated independently for resistance and reactance
components as shown in equation (2) in stead of general equation (1).
V aR + jV aX = {R 1 ( I aR +
− X 1 ( I aX +
+ j{R 1 ( I aX +
+ X 1 ( I aR +
where,
compensation factor (K xs = X 0 /X 1 × 100)
K xs :
compensation factor (K rs = R 0 /R 1 × 100)
K rs :
K xm : compensation factor (K xm = X om /X 1 × 100)
K rm : compensation factor (K rm = R om /R 1 × 100)
X: imaginary part of the measured impedance
R: real part of the measured impedance
V aX : imaginary part of phase "a" voltage
V aR : real part of phase "a" voltage
I aX : imaginary part of phase "a" current
I aR : real part of phase "a" current
R 1 R om
I 0 + R 1 I om ) + jX 1 (I a +
K rs
− 1
100
× 3I 0R +
3
K xs
− 1
100
× 3I 0X +
3
K rs
−
1
100
× 3I 0X +
3
K xs
−
1
100
× 3I 0R +
3
 55 
(1)
−
X 0 X 1 X om
I 0 + X 1 I om )
X 1
K rm
100
× 3I omR )
3
K xm
100
× 3I omX )}
3
K rm
100
× 3I omX )
3
K xm
100
× 3I omR )}
3
6 F 2 S 0 8 5 0
(2)