ABB RELION REX640 - 4.3.3 Stabilized and instantaneous differential protection for two- or three-winding transformers TR3 PTDF (ANSI 87 T3); 4.3.3.1 Identification; 4.3.3.2 Function block; 4.3.3.3 Functionality

4.3.2.11 Technical data
Table 663: TR2PTDF Technical data
Characteristic Value
Operation accuracy Depending on the frequency of the measured current:
f
n
±2 Hz
±3.0% of the set value or ±0.002 × I
n
Start time
1, 2
Low stage
High stage
Minimum Typical Maximum
31 ms
15 ms
35 ms
17 ms
40 ms
20 ms
Reset time Typically 40 ms
Reset ratio Typically 0.96
Suppression of harmonics DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5, …
4.3.3 Stabilized and instantaneous differential protection for
two- or three-winding transformers TR3PTDF (ANSI 87T3)
4.3.3.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Stabilized and instantaneous differ-
ential protection for two- or three-
winding transformers
TR3PTDF 3dI>3W 87T3
4.3.3.2 Function block
Figure 405: Function block
4.3.3.3 Functionality
The stabilized and instantaneous differential protection for two- or three-winding
transformers function TR3PTDF provides up to three three-phase current sets
or restraints designed for the protection of two-winding or three-winding
transformers and generator-transformer blocks. It is possible to have two three-
1
Current before fault = 0.0 × l
n
, f
n
= 50 Hz. Injected differential current = 2.0 × set operation value
2
Measured with static power output f
n
= 50 Hz.
Protection functions 1MRS759142 F
716 REX640
Technical Manual