Siemens SIPROTEC 7UT613 series Manual page 437

7UT613/63x Manual
C53000-G1176-C160-2
Figure 4-2 Restraining influence of 2nd harmonic in transformer differential protection
I
differential current = |I
diff
I
Rated current of protected object
NObj
I
Current at rated frequency
fN
I
Current at double frequency
2f
+ I
|
1 2
4.2 Differential Protection
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