About 2000 hp if I remember correctly?
I’m surprised they are AC but so much now is AC with electronic Controls becoming more widespread. No brushes to wear out. Controllable torque curves and probably far simpler control without series parallel, field weakening and so forth. Just a VSD and a dedicated computer/PLC I would imagine.
IGBTs have virtually taken over the small VSD market. I had no idea they would go up to this sort of size though. It doesn’t seem that long ago the drives were all thyristors but then it was the early 90s I was building Controls with them Things have moved on dramatically. Trains are now mostly AC. Even those with DC supplies. Conversely, long range power grid transmission lines are now using HVDC.