ABB REL650 - Calculating General Settings

3.1.3.1 Calculating general settings
1. Set GlobalBaseSel to 1
2. Set LineAng to 81.9º
The positive sequence impedance line angle for the protected line is calculated as
°=
÷
ø
ö
ç
è
æ
=
÷
÷
ø
ö
ç
ç
è
æ
= 9.81
5.2
5.17
arctanarctan
line
line
R
X
LineAng
GUID-A8BDC47F-A097-42F4-9C1F-DA6AB2D6AC1A V1 EN (Equation 1)
3. Set CharPGZx and CharPPZx to Mho, Quadrilateral and Combined as per the
application for each zone.
4. Set KN-factors
4.1. Set KNMag1 to 0.62
for Zone 1
4.2. Set KNAng1 to -0.6º
for Zone 1
4.3. Set KNMag2 to 0.62
For Zones 2, 3, 4, 5
4.4. Set KNAng2 to -0.6º
for Zones 2,3,4 and 5
the KN-factor is calculated for correct reach for phase-to-ground faults . The
definition of the KN-factor is:
line
lineline
Z
ZZ
KN
,1
,1,0
3×
-
=
GUID-201DAAE3-7D9E-48B9-9CCA-33B5C2E51103 V1 EN (Equation 2)
For phase-to-ground fault loops the apparent impedance is defined as:
,
, 0
3
ph Ln
ph ea
ph Ln
V
Z
I KN I
-
=
+ × ×
GUID-509FDDAF-4B92-4DD5-A9A9-B2214B58E383-ANSI V1 EN (Equation 3)
The magnitude and phase angle are set separately as KN is a complex value. The
KN-factor can be set separately for zone 1 and for the other zones. This is mainly for
application for double circuit lines where zone 1 should be set to assure underreach
and the other zones should be set to assure overreach. For a single circuit line it is
recommended to set the KN-factors to the same values.
Let Z
1,line
= 2.5 + j17.5 and Z
0,line
= 7.5 + j17.5, then KN is calculated as:
Section 3 1MRK 506 334-UUS A
REL650 setting examples
46
Application manual