ABB REL670 2.2 IEC - Page 141

I>
R
Rres
Rl
Rct Rct
Rl
UR
a) Through load situation
b) Through fault situation
UR
UR
c) Internal faults
UR
Protected Object
IEC05000427-2-en.vsd
IEC05000427 V2 EN-US
Figure 49: The high impedance principle for one phase with two current
transformer inputs
1MRK 506 369-UEN B Section 7
Differential protection
Line distance protection REL670 2.2 IEC 135
Application manual