Table 51. Positive sequence undervoltage protection (PSPTUV)
Characteristic
Value
Operation accuracy
At the frequency f = f
n
±1.5% of the set value or ±0.002 × U
n
Start time
1)2)
U
Fault
= 0.9 x set
Start
value
Typical 28 ms (±15ms)
Reset time
< 40 ms
Reset ratio
Typical 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) Residual voltage before fault = 1.1 × U
n
, f
n
= 50 Hz, residual voltage with nominal frequency injected from
random phase angle
2) Includes the delay of the signal output contact
Table 52. Positive sequence undervoltage protection (PSPTUV) main settings
Parameter
Function
Value (Range)
Step
Start value
PSPTUV
0.010...1.200 pu
0.001
Operate delay time
PSPTUV
0.040...120.000 s
0.001
Voltage block value
PSPTUV
0.01...1.0 pu
0.01
Transformer Protection and Control
1MRS756788 A
RET630
Product version: 1.0
Issued: 15.09.2009
ABB
39
Содержание RET630
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