ABB RER670 - Page 94

To calculate the zero sequence current reduction for U and V phases, see
connection example 1.
The phase selection settings for the first instance of the T1PPDIF function shall be:
PhSelW1=(L1-L2)/2
PhSelW2=L1
InvW2Curr=No
Then the internal calculations will be:
 
 
 
1
12
1
12
100 100
% IDLW1 IDLW2
2
100 100
% 1 , 2 ,
2
VU
Diff S
BaseW BaseW
VU
Bias S
BaseW BaseW
II
II
II
II
I Max IDLW IDLW Max I
II

     



   



IECEQUATION205 V2 EN-US (Equation 12)
The phase selection settings for the second instance of the T1PPDIF function shall
be:
PhSelW1=(L1-L2)/2
PhSelW2=L2
InvW2Curr=Yes
Then the internal calculations will be:
 
 
 
2
12
2
12
100 100
% IDLW1 IDLW2
2
100 100
% 1, 2 ,
2
VU
Diff R
BaseW BaseW
VU
Bias R
BaseW BaseW
II
II
II
II
I Max IDLW IDLW Max I
II

     




   



IECEQUATION206 V2 EN-US (Equation 13)
Section 6 1MRK 506 375-UEN A
Differential protection
88 Railway application RER670 2.2 IEC
Application manual