ABB Relion 670 series - Page 359

where
X1RvPPZx is the positive sequence reactance reach for phase-to-phase
fault opposite to zone direction for zone x (x=1-5 and RV)
R1RvPPZx 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,
R RvPPZx X RvPPZx
R FwPPZx
X FwPPZx
1 1
1
1
= ⋅






IECEQUATION15014 V1 EN-US (Equation 104)

AB
V
1
AB set
IZ
2
( 1 )
comp AB AB RVset
V V I Z   
1
1
comp AB AB set
V V I Z  
1
AB RVset
IZ
AB
I jX
AB
IR
ANSI 15000058 -1-en.vsdx
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
SEMOD154224-283 v2GUID-8A79E50E-9DC0-45DA-A3A7-DF3DBF59618C 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 502 066-UUS B Section 7
Impedance protection
353
Technical manual