If it is 25kV, then it is French standard. The Germanic lands
use 15kV(Austria, Germany, Switzerland)...
French locos? Metre gauge can run up to 200kmph safely. It
probably is just the loco that generates the
instability(rarefaction of rear carriages). Tilting trains would
help a lot in this situation. Italian Pendolinos?
But Pendolino like got a lot of problems leh, sometimes some
coaches won't tilt. Anyway they've got ETS already, or Electric
Train Sets from your country.