Table 55. High-impedance or flux-balance based differential protection for machines (MHZPDIF) main settings
Parameter Function Value (Range) Step
Operate value MHZPDIF 0.5...50.0% 0.1
Minimum operate time MHZPDIF 0.02...300.00 s 0.01
Table 56. Stabilized differential protection for machines (MPDIF)
Characteristic Value
Operation accuracy At the frequency f = f
n
±3% of the set value or ±0.002 × I
n
Operate time
1)2)
Biased low stage
Instantaneous high
stage
3)
Typically 40 ms (±10 ms)
Typically 15 ms (±10 ms)
Reset time <40 ms
Reset ratio Typically 0.96
Retardation time <20 ms
1) Fn = 50 Hz, results based on statistical distribution of 1000 measurements
2) Includes the delay of the high speed power output contact
3) Ifault = 2 ×
High operate value
Table 57. Stabilized differential protection for machines (MPDIF) main settings
Parameter
Function Value (Range) Step
CT connection type MPDIF 1...2 1
High operate value MPDIF 100...1000% 1
Low operate value MPDIF 5...30% 1
Slope section 2 MPDIF 10.0...50.0% 0.1
End section 1 MPDIF 0...100% 1
End section 2 MPDIF 100...300% 1
Table 58. 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 × set
Start value
Typically 17 ms (±15 ms)
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...2.00
Generator Protection and Control
1MRS757583 C
Product version: 1.3
36 ABB
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