Numerical generator protection
ABB Switzerland Ltd
Utility Automation
REG316*4
1MRK502004-Ben
Page 23
Table 32: Overexcitation (24)
Table 31: Rate-of-change of frequency df/dt (81)
Features:
· Combined pick-up with frequency criterion possible
· Blocking by undervoltage
Settings:
df/dt -10 to +10 Hz/s in steps of 0.1 Hz/s
Frequency 40 to 55 Hz in steps of 0.01 Hz at f
N
= 50 Hz
50 to 65 Hz in steps of 0.01 Hz at f
N
= 60 Hz
Delay 0.1 to 60 s in steps of 0.01 s
Minimum voltage 0.2 to 0.8 U
N
in steps of 0.1 U
N
Accuracy of df/dt (at 0.9 to 1.05 f
N
) ±0.1 Hz/s
Accuracy of frequency (at 0.9 to 1.05 f
N
) ±30 mHz
Reset ratio df/dt 95% for max. function
105% for min. function
Features:
· U/f measurement
· Minimum voltage blocking
Settings:
Pick-up value 0.2 to 2 U
N
/f
N
in steps of 0.01 U
N
/f
N
Delay 0.1 to 60 s in steps of 0.01 s
Frequency range 0.5 to 1.2 f
N
Accuracy (at f
N
) ±3% or ±0.01 U
N
/f
N
Reset ratio >97% (max.), <103% (min.)
Starting time £120 ms
Table 33: Overexcitation function with inverse time delay (24)
Features:
· Single-phase measurement
· Inverse time delay according to IEEE Guide C37.91-1985
· Setting made by help of table settings
Settings:
Table settings U/f values: (1.05; 1.10 to 1.50) U
N
/f
N
Start value U/f 1.05 to 1.20 U
N
/f
N
in steps of 0.01 U
N
/f
N
t
min
0.01 to 2 min in steps of 0.01 min
t
max
5 to 100 min in steps of 0.1 min
Reset time 0.2 to 100 min in steps of 0.1 min
Reference voltage 0.8 to 1.2 U
N
in steps of 0.01 U
N
Accuracy of pick-up value ±3% U
N
/f
N
(at f
N
)
Frequency range 0.5 to 1.2 f
N
Reset ratio 100%
Starting time <120 ms
To Next Page
Loading...
