Repurposing a VFD for a fixed frequency specialty single phase motor?

[GregBuchholz]

I'm working for a company that is making Stirling engine cryocoolers. We have a single phase, permanent magnet linear motor that reciprocates at 60Hz. You vary the amount of cooling by modulating the voltage applied the the windings. More voltage equals more linear motion, which displaces a higher volume of the working fluid, which in turn extracts more heat from the heat exchangers. Se we need a 10kW, 0-270VAC variable source of 60Hz power. It seems like a sufficiently over-sized off-the-shelf VFD has all the necessary hardware to perform the power conversion that is required to go from 3-phase 480V on the input side, to single phase variable AC voltage on the motor side, at a constant 60Hz. The problem as I see it is the embedded firmware in the VFD. Does anyone know of a VFD that has enough flexibility which would allow us to operate in a fixed frequency, variable voltage manner? Or one that allows extensive reprogramming of the internal operation of the drive? I've contacted a few VFD manufacturers, and so far the message is that they don't support something like this.

Thoughts?

 

[ozmosis]

Yep, that's the one. If they can't do it, not many can.