I was just told that many European industrial locations (mostly metal work) use 200 Hz and 300 Hz for hand tools like angle grinders! That's for two reasons, at that frequency they can use lightweight 3ph asynchronous motors that are basically indestructible, and the synchronous speed is much higher.
I saw that used in a smallish company that makes turbines for small hydro plants. All tools use green 3+Earth CEE connectors, the most common system is 265V 200 Hz.
