Permanent magnet DC Generator questions

[Zeph]

Hello, I'm a mechanical engineering student currently working on a project which involves a compressed air motor and a Permanent magnet DC generator.

I have this generator :
http://www.windstreampower.com/443905_PMDCG.php

Basically, we'll use the generator power output to determine the power output of the pneumatic motor, with that we can get the amount of air flowing through the motor.


I would like to understand how voltage will be decided. They say "Output Voltages: 12, 24, 36, 48, 90, or 120 (determined by load and rpm)"

The generator will be plugged on a variable resistance

the way I see it is that if the generator runs at 1000rpm, ill get 50Volts(1st graph)
I'd then get around 2.5Amps and 125Watts(graph 2),
would the resistance set itself to 20ohm or would the current adapt to the resistance I set?

thx for clarifying I'm a little bit confused :)

 

[berkeman]

For power conversion systems that involve a variable output impedance source, search about MPPT (maximum power point tracking):

https://en.wikipedia.org/wiki/Maximum_power_point_tracking