Table 156. Stabilized and instantaneous differential protection for two-winding transformers (TR2PTDF) main settings
Parameter Function Value (Range) Step
High operate value TR2PTDF 500...3000 %I
r
10
Low operate value TR2PTDF 5...50 %I
r
1
Slope section 2 TR2PTDF 10...50% 1
End section 2 TR2PTDF 100...500 %I
r
1
Restraint mode TR2PTDF 5 = Waveform
6 = 2.h + waveform
8 = 5.h + waveform
9 = 2.h + 5.h + wav
-
Start value 2.H TR2PTDF 7...20% 1
Start value 5.H TR2PTDF 10...50% 1
Operation TR2PTDF 1 = on
5 = off
-
Winding 1 type TR2PTDF 1 = Y
2 = YN
3 = D
4 = Z
5 = ZN
-
Winding 2 type TR2PTDF 1 = y
2 = yn
3 = d
4 = z
5 = zn
-
Zro A elimination TR2PTDF 1 = Not eliminated
2 = Winding 1
3 = Winding 2
4 = Winding 1 and 2
-
Table 157. Numerical stabilized low-impedance restricted earth-fault protection (LREFPNDF)
Characteristic
Value
Operation accuracy Depending on the frequency of the measured current: f
n
±2 Hz
±2.5% of the set value or ±0.002 x I
n
Start time
1)2)
Minimum Typical Maximum
I
Fault
= 2.0 × set
Operate value
37 ms 41 ms 45 ms
Reset time Typically 40 ms
Reset ratio Typically 0.96
Retardation time <35 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±20 ms
Suppression of harmonics DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5, …
1) Current before fault = 0.0, f
n
= 50 Hz, results based on statistical distribution of 1000 measurements
2) Includes the delay of the signal output contact
1MRS759144 A
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