Current Transformer Connections And Transformation Ratio Correction - ABB RELION REX640 Technical Manual

Section 4
Protection functions
4.3.3.6
642
Fault in protected area
(from Differential calculation)
I_D
(from Differential calculation)
BLOCK
BLK_OPR_HS
High operate value
GUID-7EF90412-1C26-4221-BF17-83FC11E3536F V1 EN
Figure 355: Operation logic of Instantaneous high stage
External blocking functionality
TR3PTDF has three inputs for blocking.
Blocking inputs
BLOCK
BLK_OPR_LS
BLK_OPR_HS

Current transformer connections and transformation ratio correction

The combinations of the connections of the primary current transformers are
designated as "Type 1" and "Type 2". The type needs to be selected separately for the
combination of CT connections on the winding 1 and 2 sides as well as for the
combination of CT connections on the winding 1 and 3 sides in case of three-winding
transformer.
• If the positive directions of the winding 1 and winding 2 relay currents are
opposite, the setting parameter CT connection 1-2 is "Type 1", as shown in
356
• If the positive directions of the winding 1 and winding 2 relay currents are equal,
the setting parameter CT connection 1-2 is "Type 2", as shown in
• The default value of the CT connection 1-2 settings is "Type 1".
• The same applies for the CT connection 1-3 settings.
Description
When active (TRUE), the operation of the function is blocked; only
measurement value outputs are updated.
When active (TRUE), TR3PTDF acts normally except that the OPR_LS
output is not active or activated in any circumstances. Additionally, the
OPERATE output can be activated only by the instantaneous high stage
(if not blocked).
When active (TRUE), TR3PTDF acts normally except that the OPR_HS
output is not active or activated in any circumstances. Additionally, the
OPERATE output can be activated only by the biased low stage (if not
blocked).
1MRS759142 C
OPERATE
OPR_HS
Figure
Figure 357
REX640
Technical Manual