[logik-des-frequenzschutzes, 1, en_GB]
Figure 2-42 Logic diagram of the frequency protection
Setting Notes
General
Frequency protection is only in effect and accessible if address 142 FREQUENCY Prot. is set to Enabled
during configuration of protective functions. If the function is not required Disabled is set. Address 4201
O/U FREQUENCY serves to switch the function ON or OFF or to block only the trip command (Block relay).
Pickup Values
By configuring the rated frequency of the power system and the frequency threshold for each of the stages f1
PICKUP to f4 PICKUP in each case the function is established as either overvoltage or undervoltage protec-
tion. Set the pickup threshold lower than nominal frequency if the element is to be used for underfrequency
protection. Set the pickup threshold higher than nominal frequency if the element is to be used for overfre-
quency protection.
NOTE
If the threshold is set equal to the nominal frequency, the element is inactive.
For the f4 frequency stage, the former applies only if the parameter 4214 THRESHOLD f4 is set to auto-
matic (default setting). If desired, this parameter can also be set to f> or f<, in which case the evaluation
direction (increase or decrease detection) can be specified independent of the parametrized f4 PICKUP
threshold.
If frequency protection is used for network decoupling and load shedding purposes, settings depend on the
actual network conditions. Normally a graded load shedding is strived for that takes into account priorities of
consumers or consumer groups.
Further application examples are covered under power stations. The frequency values to be set mainly
depend, also in these cases, on power system/power station operator specifications. In this context, frequency
decrease protection ensures the power station's own demand by disconnecting it from the power system on
time. The turbo regulator regulates the machine set to the nominal speed. Consequently, the station's own
demands can be continuously supplied at nominal frequency.
2.6.2
Functions
2.6 Frequency Protection
SIPROTEC 4, 7VE61 and 7VE63, Manual 89
C53000-G1176-C163-3, Edition 10.2017
To Next Page
Loading...
Need help?
General
