Numerical generator protection
ABB Switzerland Ltd
Utility Automation
REG316*4
1MRK502004-Ben
Page 15
Table 13: Directional definite time overcurrent protection (67)
· Directional overcurrent protection with detection of the power direction
· Backup protection for distance protection scheme
· Three-phase measurement
· Suppression of DC- and high-frequency components
· Definite time characteristic
· Voltage memory feature for close faults
Settings:
Current 0.02 to 20 I
N
in steps of 0.01 I
N
Angle -180° to +180° in steps of 15°
Delay 0.02 s to 60 s in steps of 0.01 s
tWait 0.02 s to 20 s in steps of 0.01 s
Memory duration 0.2 s to 60 s in steps of 0.01 s
Accuracy of pick-up setting (at f
N
)
Reset ratio
Accuracy of angle measurement
(at 0.94 to 1.06 f
N
)
±5% or ±0.02 I
N
>94%
±5°
Voltage input range
Voltage memory range
Accuracy of angle measurement at voltage mem-
ory
Frequency dependence of angle measurement
at voltage memory
Max. Response time without delay
0.005 to 2 U
N
<0.005 U
N
±20°
±0.5°/Hz
60 ms
Table 14: Directional inverse time overcurrent function (67)
· Directional overcurrent protection with detection of the power direction
· Backup protection for distance protection scheme
· Three-phase measurement
· Suppression of DC- and high-frequency components
· Inverse time characteristic
· Voltage memory feature for close faults
Settings:
Current I-
Start
1…4 I
B
in steps of 0.01 I
B
Angle -180°…+180° in steps of 15°
Inverse time characteristic
(acc. to B.S. 142 with extended setting range)
normal inverse
very inverse
extremely inverse
long-time earth fault
t=k
1
/ ((I/I
B
)
C
-1)
c = 0,02
c = 1
c = 2
c = 1
k
1
-setting 0.01 to 200 s in steps of 0.01 s
t-min 0 to 10 s in steps of 0.1 s
IB-value 0.04 to 2.5 I
N
in steps of 0.01 I
N
tWait 0.02 s to 20 s in steps of 0.01 s
To Next Page
Loading...
