The default setting is a reasonable value. Siemens recommends using the default setting.
7.20.4
Stage Description
7.20.4.1
Description
Logic of the Stage
[lo_load shedding_stage, 1, en_US]
Figure 7-165
Pickup and Operate
If the following 3 conditions are all fulfilled, a Pickup indication is issued:
•
The frequency value drops below the Threshold.
•
The Blocking input from the function block General is inactive.
•
The preceding 2 conditions are fulfilled during the configured number of frequency measurement cycles
(cycle time = 10 ms). You can set the number with the parameter f< stabilization counter.
SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017
Logic Diagram of the Underfrequency Load Shedding Stage
Protection and Automation Functions
7.20 Underfrequency Load Shedding
841