Directional Earth-Fault Protection (Defxpdef) - ABB RET620 Product Manual

Transformer Protection and Control
RET620
Product version: 2.0
Table 35. Directional earth-fault protection (DEFxPDEF)
Characteristic
Operation accuracy
1)2)
Start time
Reset time
Reset ratio
Retardation time
Operate time accuracy in definite time mode
Operate time accuracy in inverse time mode
Suppression of harmonics
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
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
Start value = 2.5 x I Start value multiples in range of 1.5 to 20
3) Maximum ,
n
30
DEFLPDEF
DEFHPDEF
DEFHPDEF
Start value
I = 2 x set
Fault
DEFLPDEF
I = 2 x set Start value
Fault
Value
Depending on the frequency of the current measured: f
Current:
±1.5% of the set value or ±0.002 x I
Voltage
±1.5% of the set value or ±0.002 x U
Phase angle:
±2°
Current:
±1.5% of the set value or ±0.002 x I
(at currents in the range of 0.1...10 x I
±5.0% of the set value
(at currents in the range of 10...40 x I
Voltage:
±1.5% of the set value or ±0.002 x U
Phase angle:
±2°
Minimum Typical
42 ms 44 ms
61 ms 64 ms
< 40 ms
Typical 0.96
< 30 ms
±1.0% of the set value or ±20 ms
±5.0% of the theoretical value or ±20 ms
RMS: No suppression
DFT: -50 dB at f = n x f , where n = 2, 3, 4, 5,...
n
Peak-to-Peak: No suppression
1MRS757846 A
±2 Hz
n
n
n
n
)
n
)
n
n
Maximum
46 ms
66 ms
3)
, f = 50 Hz, earth-fault current
n n
ABB