Where
T
Inv
Inverse-time delay
T
p
Time multiplier (Parameter
Time dial
)
V
Measured undervoltage
V
thresh
Threshold value (Parameter
Threshold
)
k
Curve constant k (Parameter
Charact. constant k
)
α
Curve constant α (Parameter
Charact. constant α
)
c
Curve constant c (Parameter
Charact. constant c
)
Dropout
The greater dropout differential (=
| pickup value – dropout value |
) of the following 2 criteria
applies:
Dropout differential derived from the parameter
Dropout ratio
If this parameter is not available, a dropout ratio of 95 % applies for the overvoltage and of 105 % for the
undervoltage functionality.
Minimum absolute dropout differential
150 mV sec.
Times
Pickup time
Approx. 25 ms + OOT
58
at 50 Hz
Approx. 22 ms + OOT at 60 Hz
Dropout time
Approx. 20 ms + OOT
Frequency Operating Range
0.9 ≤ f/f
rated
≤ 1.1
According to specified tolerances
10 Hz ≤ f < 0.9 f
rated
1.1 f
rated
< f ≤ 90 Hz
Slightly expanded tolerances
f < 10 Hz
f > 90 Hz
Inactive
Tolerances for Stage Type Definite Time-Undervoltage Protection
Voltages
0.5 % of the setting value or 0.05 V
Time delays
1 % of the setting value or 10 ms
Tolerances for Stage Type Inverse Time-Undervoltage Protection
Voltages
0.5 % of the setting value or 0.05 V
Operate time for 0 < V/V
Thresh
< 0.9
5 % of the setting value or 30 ms
Reset time delay
1 % of the setting value or 10 ms
Undervoltage Protection with Positive-Sequence Voltage
Setting Values
Threshold value
0.300 V to 200.000 V
Increments of 0.001 V
Time delay
0.00 s to 60.00 s
Increments of 0.01 s
11.19.7
58
OOT (Output Operating Time) additional delay of the output medium used, see chapter
Technical Data
11.19 Voltage Protection
SIPROTEC 5, Low-Impedance Busbar Protection, Manual
963
C53000-G5040-C019-C, Edition 04.2021
