ABB REG630 - Page 32

Table 42. High-impedance based restricted earth-fault protection (HREFPDIF)
Characteristic Value
Operation accuracy At the frequency f = f
n
±1.5% of the set value or ±0.002 × I
n
Start time
1)2)
I
Fault
= 2.0 × set Operate value
I
Fault
= 10.0 × set Operate value
Typically 22 ms (±5 ms)
Typically 15 ms (±5 ms)
Reset time <60 ms
Reset ratio Typically 0.96
Retardation time <60 ms
Operate time accuracy in definite time mode ±1.0% of the set value or ±20 ms
1) Current before fault = 0.0 × I
n
, f
n
= 50 Hz
2) Includes the delay of the signal output contact
Table 43. High-impedance based restricted earth-fault protection (HREFPDIF) main settings
Parameter
Function Value (Range) Step
Operate value HREFPDIF 0.5...50.0% 0.1
Minimum operate time HREFPDIF 0.020...300.000 s 0.001
Table 44. Rotor earth-fault protection (MREFPTOC)
Characteristic
Value
Operation accuracy At the frequency f = f
n
±1.5% of the set value or ±0.002 × I
n
Start time
1)2)
Typically 25 ms (±15 ms)
Reset time <50 ms
Reset ratio Typically 0.96
Retardation time <50 ms
Operate time accuracy ±1.0% of the set value of ±20 ms
Suppression of harmonics -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
1) Current before fault = 0.0 × 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
Table 45. Rotor earth-fault protection (MREFPTOC) main settings
Parameter
Function Value (Range) Step
Alarm start value MREFPTOC 0.010...2.000 pu 0.001
Operate start value MREFPTOC 0.010...2.000 pu 0.001
Alarm delay time MREFPTOC 0.04...200.00 s 0.01
Operate delay time MREFPTOC 0.04...200.00 s 0.01
Generator Protection and Control
1MRS757583 C
REG630
Product version: 1.3
32 ABB