I know 400Hz is used on aircraft because xfmrs and motors need far less iron and copper, and this results in weight savings that in aviation applications are more important than the lower energy efficiency involved with such a high frequency.
I wasn't aware that 400Hz was used on ships. Space savings would seem to be a good reason.
It is not possible to get 400Hz from 60Hz using a rotary converter. They require different shaft speeds. If the second frequency is a multiple or submultiple of the first, you can use a shaft or a direct drive motor-generator (well, after adjusting for the slip). I guess they must use belt- or gear-driven motor-generators, or VFDs, or something like that.
Any aviation workers out there?
[This message has been edited by yaktx (edited 02-01-2006).]
