U.S. Drives in Niagara Falls, N.Y. makes units up to 3500HP, which use step down and step up transformers. See their white paper on the subject by going to
Siemens made 6 units for TCPL at 44MW each and running speed of 5200rpm. These motors start and run like a dream. just like starting an engine revs build slowly and accelerate at an even rate, and rapid through critical speeds. They are synchronous motors
Drivemaster,
The only manufacturer I know of that makes a true 13.8kV drive is Robicon, now a part of Siemens. Robicon 13.8kV drives link The problem is that 2.45MW is somewhat small in that voltage range so you may end up with a larger capacity than necessary with a nameplate that says it is smaller.
As far as I know, all of the others (ABB, Toshiba, GE, Alstom, and even Siemens prior to buying Robicon), do it by using transformers on either side and a lower voltage (4.2-6.6kV) drive, which adds significant losses to the system. That kind of system works, but makes it even more expensive because the output transformer must be specially designed to function in a variable frequency environment.
Also, IMHO you should definately stay away from someone like US Drives who would do it by transforming down to 575V and back up. Do the math. At 2.45MW, the current at 575V is going to be astronomical!
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