ABB 650 series Applications Manual page 46

Section 4
Analog inputs
40
Transformer
Transformer and
Line protection
Setting of current input
for transformer functions:
Set parameter
CTStarPoint with
Transformer as
reference object.
Correct setting is
"ToObject"
IEC05000462 V2 EN-US
Figure 7: Example how to set CTStarPoint parameters in the IED
Figure 8:
For busbar protection, it is possible to set the CTStarPoint parameters in two ways.
The first solution will be to use busbar as a reference object. In that case for all CT
inputs marked with 1 in Figure 8, set CTStarPoint = ToObject, and for all CT
inputs marked with 2 in Figure 8, set CTStarPoint = FromObject.
The second solution will be to use all connected bays as reference objects. In that
case for all CT inputs marked with 1 in Figure 8, set CTStarPoint = FromObject,
and for all CT inputs marked with 2 in Figure 8, set CTStarPoint = ToObject.
Regardless which one of the above two options is selected, busbar differential
protection will behave correctly.
The main CT ratios must also be set. This is done by setting the two parameters
CTsec and CTprim for each current channel. For a 1000/1 A CT, the following
settings shall be used:
• CTprim = 1000 (value in A)
• CTsec =1 (value in A).
IED
Setting of current input
for transformer functions:
Set parameter
CTStarPoint with
Transformer as
reference object.
Correct setting is
"ToObject"
1MRK 511 423-UEN A
Line
Reverse Forward
Definition of direction
for directional
line functions
Setting of current input
for line functions:
Set parameter
CTStarPoint with
Line as
reference object.
Correct setting is
"FromObject"
Bay control REC650 2.2 IEC
Application manual