Table 33. Directional earth-fault protection (DEFxPDEF)
Characteristic
Value
Operation accuracy
At the frequency f = f
n
DEFLPDEF
Current:
±1.5% of the set value or ±0.002 x I
n
Voltage
±1.5% of the set value or ±0.002 x U
n
Phase angle: ±2°
DEFHPDEF
Current:
±1.5% of the set value or ±0.002 x I
n
(at currents in the range of 0.1…10 x I
n
)
±5.0% of the set value
(at currents in the range of 10…40 x I
n
)
Voltage:
±1.5% of the set value or ±0.002 x U
n
Phase angle: ±2°
Start time
1)2)
DEFHPDEF and
DEFLPTDEF:
I
Fault
= 2 x set
Start
value
Typical 54 ms (±15 ms)
Reset time
< 40 ms
Reset ratio
Typical 0.96
Retardation time
< 30 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
RMS: No suppression
DFT: -50dB at f = n x f
n
, where n = 2, 3, 4, 5,
…
Peak-to-Peak: No suppression
1) Set
Operate delay time
= 0.06 s,
Operate curve type
= IEC definite time,
Measurement mode
= default (depends on
stage), current before fault = 0.0 x I
n
, f
n
= 50 Hz, earth-fault current with nominal frequency injected from
random phase angle, results based on statistical distribution of 1000 measurements
2) Includes the delay of the signal output contact
3) Maximum
Start value
= 2.5 x I
n
,
Start value
multiples in range of 1.5 to 20
Transformer Protection and Control
1MRS756788 A
RET630
Product version: 1.0
Issued: 15.09.2009
30
ABB
Содержание RET630
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