ABB REG650 - Page 39

Differential protection
Table 23. Transformer differential protection T2WPDIF, T3WPDIF
Function Range or value Accuracy
Operating characteristic Adaptable ± 1.0% of Ir for I < Ir
± 1.0% of I for I > Ir
Reset ratio >94% -
Unrestrained differential current limit (1.00-50.00)x IBase on
high voltage winding
± 1.0% of set value
Base sensitivity function (0.05 - 0.60) x IBase ± 1.0% of Ir
Minimum negative sequence current (0.02 - 0.20) x IBase ± 1.0% of Ir
Operate angle, negative sequence (30.0 - 90.0) degrees ± 1.0 degrees
Second harmonic blocking (5.0-100.0)% of
fundamental differential
current
± 2.0% of applied harmonic magnitude
Fifth harmonic blocking (5.0-100.0)% of
fundamental differential
current
± 12.0% of applied harmonic magnitude
Connection type for each of the windings Y or D -
Phase displacement between high voltage
winding, W1 and each of the windings, W2
and W3. Hour notation
0–11 -
Operate time, restrained function 25 ms typically at 0 to 5 x
set level
-
Reset time, restrained function 25 ms typically at 5 to 0 x
set level
-
Operate time, unrestrained function 20 ms typically at 0 to 5 x
set level
-
Reset time, unrestrained function 25 ms typically at 5 to 0 x
set level
-
Table 24. Restricted earth-fault protection, low impedance REFPDIF
Function
Range or value Accuracy
Operate characteristic Adaptable ± 1% of IBase if Ibias < 1.25 IBase (i.e. base sensitivity in section 1 of the
operate - restrain characteristic)
± 2% of theoretical operate value (Idiff) if Ibias >= 1.25 IBase (i.e. sections
2 and 3)
(The above is valid if IBase is equal to the protected winding rated current.)
Reset ratio 0.95 -
Directional characteristic, for zero
sequence directional function
ROA ± 60 to ± 90 degrees ± 1 degrees at Ibias = IBase
± 2 degrees at Ibias = 2 * IBase
± 3 degrees at Ibias = 4 * IBase
(The above is valid if IBase is equal to the protected winding rated current.)
Operate time, trip function 25 ms typically at 0 to 10 x IdMin -
Reset time, trip function 30 ms typically at 10 to 0 x IdMin -
Generator protection REG650
1MRK 502 050-BEN B
Product version: 1.3
ABB 39