SFRS 1

[electpower]

I was preparing list of signals between high voltage switchyard and power plant. I met with a signal SFRS -On and SFRS - OFF ( For a Generator operating under SFRS)
Can some one tell me what does "SFRS" mean ? What is it?

 

[ijl]

Maybe "Secondary Frequency Regulation System"

I found the following description:
"Secondary Frequency Control takes place in the time scale from 5 seconds up to 10 minutes after the change in frequency. Improved Secondary Frequency Control can be achieved by use of a Secondary Frequency Regulation System which acts directly on the MW Outputs of participating generation units."