PTO Generator

[TugboatEng]

I have an idea that requires a generator that can produce 10-20kW of power over an available speed range of 650-1800 rpm, it's essentially the same application as an automotive alternator. I can use a step up gearbox if necessary. I eventually need it to be 480V 3 phase. I'm looking for guidance with regards to the best type of generator to achieve this output. Bonus if it can be motorized.

 

[waross]

Some suggestions come to mind;
1> Look for an inverter that will accept a variable frequency input.
2> I haven't used one but I have seen literature for a variable speed hydraulic drive. Variable speed pump input. Controlled speed motor output. See what google brings. This would allow a conventional alternator to be driven at a constant 60 Hz (or 400 Hz, if you can use that).
3> A DC to AC inverter with a DC generator similar to an automotive alternator.
I am thinking about the phenomena of "Load Dump" in alternator circuits.
With the engine at higher revs, and the loss of a large loads, the alternator output may reach or exceed 100 Volts.
I am thinking a 100 Amp alternator geared up from your 650 RPM prime mover until 100 Volts output is reached. Use a modified AVR.and feed the alternator output to an inverter.
I'll leave the details to you if you like this solution.