Setting The Reach With Respect To Load - ABB REG670 Applications Manual

Section 8
Impedance protection
8.2.3.6
206
Z 0
m
= -
K 0 1
× + +
2 Z 1 Z 0 R
f
EQUATION1426 V1 EN
If the denominator in equation
real and imaginary part of the reach reduction factor for the overreaching zones can be
written as:
×
X m 0 Re
( )
= -
Re K 0 1
( )
2
+
Re B Im
EQUATION1427 V2 EN
( )
×
( ) X m 0 Im
=
Im K 0
( )
2
+
Re B Im
EQUATION1428 V2 EN
Parallel line is out of service and earthed in both ends
Apply the same measures as in the case with a single set of setting parameters. This
means that an underreaching zone must not overreach the end of a protected circuit for
the single phase-to-earth faults.
Set the values of the corresponding zone (zero-sequence resistance and reactance)
equal to:
2
æ
X
m0
×
ç ------------------------- -
R = R 1 +
0E 0
2
è
R + X
0 0
EQUATION561 V1 EN
2
æ
X
m0
×
X = X ç 1 – ------------------------- -
0E 0
2
è
R + X
0 0
EQUATION562 V1 EN

Setting the reach with respect to load

Set separately the expected fault resistance for phase-to-phase faults RFPPZx and for
the phase-to-earth faults RFPEZx for each zone. For each distance zone, set all
remaining reach setting parameters independently of each other.
The final reach in the resistive direction for phase-to-earth fault loop measurement
automatically follows the values of the line-positive and zero-sequence resistance,
and at the end of the protected zone is equal to equation 68.
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
63 is called B and Z0m is simplified to X0m, then the
( )
B
( )
2
B
B
( )
2
B
ö
÷
2
ø
ö
÷
2
ø
1MRK 502 071-UEN -
(Equation 63)
(Equation 64)
(Equation 65)
(Equation 66)
(Equation 67)
Application manual