2. APPLICATION
GEK-106243E
DTP Digital Transformer Protection
2-7
11. Check the mismatch error:
5.00/2.5 - 1.75/0.87
Windings A-B:
⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯
= -0.005%
5.00/2.5
5.00/5.00 - 1.75/1.75
Windings B-C:
⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯
= 0.000%
5.00/2.5
5.00/2.5 - 1.75/0.87
Windings C-A:
⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯
= -0.005%
5.00/2.5
This check is O.K. since all of the mismatch errors are less than 5%.
In case of obtaining a high error, the unbalance will always be covered by the percentage restraint setting,
although it is not recommended to have errors over 20% (including the variation due to the possible tap
changer of the transformer). Nevertheless, the DTP relay has a high tap range, in 0.01 In steps, so that there
will always be available taps very close or exact to the current values, reaching minimum errors.
NOTE 1: For this example, a multi-ratio toroidal transformer type ANSI C100 has been chosen. In other cases, the
CT ratio can be fix, or the transformers can be dedicated.
Summary of Contents for DTP-B
Page 23: ...3 OPERATING PRINCIPLES 3 6 DTP B Digital Transformer Protection GEK 106243E ...
Page 53: ...10 INSTALLATION AND MAINTENANCE 10 2 DTP B Digital Transformer Protection GEK 106243E ...
Page 68: ...12 FIGURES GEK 106243E DTP Digital Transformer Protection 12 3 Figure 3 RS 232 Connection ...
Page 69: ...12 FIGURES 12 4 DTP B Digital Transformer Protection GEK 106243E Figure 4 Dimensions Diagram ...
Page 70: ...12 FIGURES GEK 106243E DTP Digital Transformer Protection 12 5 Figure 5 Front View ...
