ABB RELION RET670 - Page 169

ANSI05000427-2-en.vsd
I>
R
Rres
Rl
Rct
Rct
Rl
VR
a) Through load situation
b) Through fault situation
VR
VR
c) Internal faults
VR
Protected Object
ANSI05000427 V2 EN-US
Figure 55: The high impedance principle for one phase with two current
transformer inputs
1MRK 504 163-UUS A Section 7
Differential protection
Transformer protection RET670 2.2 ANSI 163
Application manual