Hitachi Relion 670 Series Applications Manual page 89

1MRK506375-UEN Rev. N
PhSelW1=(L1-L2)/2
PhSelW2=(L1-L2)/2
InvW2Curr=No
Then the internal calculations will be:
 

I %
Diff
 

I %
Bias
IECEQUATION207 V2 EN-US
Transformer connection – example 5
110/15kV
U
V
IEC15000174 V3 EN-US
Figure 38:
The starpoint of the 110/15kV railway transformer can either be earthed (via coil) or isolated.
For information on how to arrange the differential protection for this transformer, see example 2.
6.2.5.2 How to wire the transformer differential protection to the IED using CTs
Here are two examples of how to wire and connect a star-connected, two-phase CT (on the high-
voltage side) and a one-phase CT (on the low-voltage side) to the IED for protection of a railway
power transformer (shown in Figure 33) using the T1PPDIF function.
Railway application RER670
Application manual

100 I I
  
V U
IDLW1 IDLW2
I 2
BaseW 1


 


Max IDLW 1 , IDLW 2 Max

I

I
U
110kV
I
v
Transformer connection – example 5
For the correct terminal designations, see the connection diagrams valid for the delivered
IED.
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
100 I I
 
S R
I 2
BaseW 2

  
100 I I 100 I I
 

V U S R
,

2 I 2

BaseW 1 BaseW 2
Section 6
Differential protection
(Equation 14)
GUID-B0B4EFFC-DA6B-47F3-8B72-70255DC783F9 v2
R
15kV
I
s
S
IEC15000174-3-en.vsdx
GUID-E732B4DC-77E3-4142-829E-D08F9677B789 v1
83