This graph is for thevwestern US, I think it said 80 million population. The Misoperations is explained in the text. I noticed that most of the problems seem to be with microprocessors. That must mean there are bugs in the systems. Maybe hardware? Or if the hardware is redundant, then probably software?
https://www.wecc.org/epubs/StateOfTheInterconnection/Pages/Misoperations0706-4202.aspx
