![background image](http://html1.mh-extra.com/html/abb/relion-670-series/relion-670-series_applications-manual_3052129264.webp)
X
0E
X
0
1
X
m0
2
R
0
2
X
0
2
+
--------------------------
–
è
ø
ç
÷
æ
ö
×
=
EQUATION562 V1 EN-US
(Equation 235)
7.5.3.6
Setting of reach in resistive direction
SEMOD154704-76 v1
Set the resistive reach independently for each zone, for phase-to-earth loop (
RIPE)
measurement.
Set separately the expected fault resistance for the phase-to-earth faults (
RFPE) for each zone.
Set all remaining reach setting parameters independently of each other for each distance zone.
The final reach in 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
R
1
3
---
2 R1PE
×
R0PE
+
(
)
RFPE
+
=
EQUATION567 V1 EN-US
(Equation 236)
2 X1PE + X0
arctan
2 R1PE + R0
loop
j
é
ù
×
ê
ú
=
×
ê
ú
ë
û
EQUATION1457 V1 EN-US
(Equation 237)
Setting of the resistive reach for the underreaching zone1 should follow the condition:
4.5
1
RFPE
X
£
×
EQUATION569 V2 EN-US
(Equation 238)
7.5.3.7
Load impedance limitation, without load encroachment function
SEMOD154704-91 v2
The following instructions is valid when the load encroachment function is not activated
(
OperationLdCmp is set to Off). If the load encroachment function is to be used for all or some
of the measuring zones, the load limitation for those zones according to this chapter can be
omitted. Check the maximum permissible resistive reach for any zone to ensure that there is a
sufficient setting margin between the IED boundary and the minimum load impedance. The
minimum load impedance (Ω/phase) is calculated as:
Z
loadmin
U
2
S
-------
=
EQUATION571 V1 EN-US
(Equation 239)
Where:
U
is the minimum phase-to-phase voltage in kV
S
is the maximum apparent power in MVA.
The load impedance [Ω/phase] is a function of the minimum operation voltage and the
maximum load current:
Section 7
1MRK 505 343-UEN B
Impedance protection
258
Application manual
Summary of Contents for Relion 670 series
Page 1: ...RELION 670 SERIES Line differential protection RED670 Version 2 1 IEC Application manual...
Page 2: ......
Page 40: ...34...
Page 64: ...58...
Page 150: ...144...
Page 406: ...400...
Page 472: ...466...
Page 494: ...488...
Page 512: ...506...
Page 524: ...518...
Page 604: ...598...
Page 686: ...680...
Page 718: ...712...
Page 722: ...716...
Page 758: ...752...
Page 759: ...753...