Rolling power outages... We often hear about them, but do not know what they are.
When it is necessary to release the power system from excess load, either automatically or with the help of a dispatcher's command, the consumers are disconnected.
How does this happen? The control signal comes from some large substation, diverges into smaller ones, then even smaller ones - it all resembles a fan
So the fan is needed not only to "return a person to his senses", but also to return the energy system to his senses. Of course, this is called a cascade transmission of information, but it looks like a fan if depicted in the form of such a scheme (approximately as in the figure below).
Signals are sent from the control high-voltage substation to lower-voltage ones. The lines diverge further and the consumers are disconnected. These consumers are predetermined who will be disconnected in the event of such situations either manually or automatically in the name of saving the power system.
This is necessary when there is a lack of active power. The generator produces, say, 6 gigawatts, and the power is needed for the power system 8 gigawatts.
To somehow cover this imbalance, 2 gigawatts must be turned off. When can there be a lack of active power? For example, the power units of the power plant stopped, the wind park became - the wind stopped blowing sharply or the sun had already gone down behind the clouds, that is, there was a sharp shortage of active power.
But since it is impossible to enter power instantly, it is necessary to immediately turn off the consumers or turn on the rotating reserve. If this rolling shutdown is not made, then the frequency at power plants will begin to decrease. And a decrease in frequency will be followed by a decrease in the generation of the mechanism in the power plant itself further and ultimately this will result in a cascade of many other power plants.
To prevent this from happening, there is a special automation - this is automatic frequency division (AFD), which does not allow such a situation.
P.S. Put likeif this article was interesting and useful to you, comment and subscribe to the ASUTPP channel!