ABB RELION 670 Series Technical Manual page 359

1MRK 502 066-UUS B
where
X1RvPPZx
R1RvPPZx
1
R RvPPZx
IECEQUATION15014 V1 EN-US
ANSI15000058 V1 EN-US
Figure 179: 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
Technical manual
is the positive sequence reactance reach for phase-to-phase
fault opposite to zone direction for zone x (x=1-5 and RV)
is the positive sequence resistive reach for phase-to-phase
fault opposite to zone direction for zone x (x=1-5 and RV) and is
internally calculated according to the equation below,
1
R FwPPZx

1
X RvPPZx
= ⋅

X FwPPZx 1


I jX
AB

I Z 1
AB set

I Z 1
AB RVset



  
V V I Z 1
comp 1 AB AB set

V
AB
   
V V ( I Z
comp 2 AB AB
I
AB
ANSI15000058-1-en.vsdx
Impedance protection
(Equation 104)
1 )
RVset

R
GUID-8A79E50E-9DC0-45DA-A3A7-DF3DBF59618C v1
K
Section 7
SEMOD154224-283 v2
is,
N
353