Rate Of Frequency Change Protection - Siemens Siprotec 5 7SS85 Techical Data

Technical Data

11.29 Rate of Frequency Change Protection

11.29 Rate of Frequency Change Protection
Setting Values for the Function
Minimum voltage
Measuring window
Setting Values for Stage Types
Threshold
Dropout differential
Operate delay
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
Times
Pickup time
Dropout time
Frequency Operating Range
0.9 ≤ f/f ≤ 1.1
rated
10 Hz ≤ f < 0.9 f
1.1 f < f ≤ 80 Hz
rated
f < 10 Hz
f > 80 Hz
Tolerances
Threshold,
measuring window > 3 periods
Threshold,
measuring window ≤ 3 periods
Minimum voltage
Time delays
Functional Measured Value
Value
df/dt
610
3.000 V to 175.000 V
2 periods to 5 periods
0.1 Hz/s to 20.0 Hz/s
0.02 Hz/s to 0.99 Hz/s
0.00 s to 60.00 s
Approx.165 ms to 225 ms (depends on measuring window length)
Approx.165 ms to 225 ms (depends on measuring window length)
According to specified tolerances
Slightly expanded tolerances
rated
Inactive
Approx. 3 % or 0.06 Hz/s
Approx. 5 % or 0.06 Hz/s
1 % of the setting value or 0.5 V
1 % of the setting value or 10 ms
Description
Calculated rate of frequency change
Increments of 0.001 V
Increments of 1 period
Increments of 0.1 Hz/s
Increments of 0.01 Hz/s
Increments of 0.01 s
150 mV sec.
SIPROTEC 5, Low-Impedance Busbar Protection 7SS85, Manual
C53000-G5040-C019-6, Edition 06.2016