ABB RELION 670 Series Technical Manual page 319

1MRK 502 066-UUS B
For Zone 1,
For Zone 2-5 and RV,
ANSI15000058 V1 EN-US
Figure 156: Simplified offset mho characteristic and voltage vector for phase A to B fault
Operation occurs if 90°≤β≤270 °.
Phase-to-ground fault
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
Technical manual
1
Z
RVset
IECEQUATION15015 V1 EN-US
Z 1
RVset
IECEQUATION15016 V1 EN-US

I jX
AB
V

I Z 1
AB set
V
AB

I Z 1
AB RVset
1 1 1
R PPZ j X PPZ
= + ⋅
R Zx 1 j X Zx 1
= + ⋅
  
V I Z 1
comp 1 AB AB set

   
V V ( I Z 1
comp 2 AB AB RVset

I
AB
ANSI15000058-1-en.vsdx
Impedance protection
1
(Equation 88)
(Equation 89)
)
R
GUID-DB8CF641-0D3F-4F7A-A628-829F3DB0AC5B v1
N
Section 7
SEMOD154224-283 v2
is,
313