ABB RELION 650 SERIES, Technical Manual

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
1 2 L L
U
1 2
1
L L set
I Z

2 1 2 1 2
( 1 )
comp L L L L set
U U I Z
  

1 1 2 1 2
1
comp L L L L set
U U I Z
 

1 2 L L
I jX

1 2 L L
I R

1 2
1
L L set
I Z

IEC15000058-2-en.vsdx
IEC15000058 V2 EN-US
Figure 38: Simplified offset mho characteristic and voltage vector for phase L1
to L2 fault
Operation occurs if 90°≤β≤270 °.
Phase-to-earth fault
SEMOD154224-283 v2 GUID-DB8CF641-0D3F-4F7A-A628-829F3DB0AC5B v1
The measuring of earth faults uses earth return compensation applied in a
conventional way. The compensation voltage is derived by considering the
influence from the earth return path.
Compensation for earth return path for faults involving earth is done by setting the
positive and zero sequence impedance of the line. It is known that the ground
compensation factor K
N
is,
1MRK 506 382-UEN A
Section 6
Impedance protection
Line distance protection REL650 2.2 IEC 105
Technical manual