Table 45. Three-phase overvoltage protection (PHPTOV)
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
= 2.0 x set
Start
value
Typical 17 ms (±15ms)
Reset time
< 40 ms
Reset ratio
Depends of the set
Relative hysteresis
Retardation time
< 35 ms
Operate time accuracy in definite time mode
±1.0% of the set value or ±20 ms
Operate time accuracy in inverse time mode
±5.0% of the theoretical value or ±20 ms
3)
Suppression of harmonics
DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,
…
1)
Start value
= 1.0 × U
n
, Voltage before fault = 0.9 × U
n
, f
n
= 50 Hz, overvoltage in one phase-to-phase with
nominal frequency injected from random phase angle
2) Includes the delay of the signal output contact
3) Maximum
Start value
= 1.20 × U
n
,
Start value
multiples in range of 1.10 to 2.00
Table 46. Three-phase overvoltage protection (PHPTOV) main settings
Parameter
Function
Value (Range)
Step
Start value
PHPTOV
0.05...1.60 pu
0.01
Time multiplier
PHPTOV
0.05...15.00
0.05
Operate delay time
PHPTOV
0.40...300.000 s
0.10
Operating curve
type
1)
PHPTOV
Definite or inverse time
Curve type: 5, 15, 17, 18, 19, 20
1) For further reference please refer to the Operating characteristics table
Transformer Protection and Control
1MRS756788 A
RET630
Product version: 1.0
Issued: 15.09.2009
36
ABB
Содержание RET630
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