Engine & Generator - Can Speed Increase Work?

[aa_0004]

is it possible by increasing speed to 3000 rpm from 1500 rpm and reduce the hp half of engine that operates the alternator(for example in case 15hp engine reduce to 7.5hp for doing same work by doubling the rpm)?

 

[russ_watters]

is it possible by increasing speed to 3000 rpm from 1500 rpm and reduce the hp half of engine that operates the alternator(for example in case 15hp engine reduce to 7.5hp for doing same work by doubling the rpm)?

Welcome to PF!

It isn't totally clear to me what you are trying to do, but in general, no. The electrical load on an alternator is what determines the mechanical power input required. So what happens to the power depends on what happens to the load when you increase the rpm (frequency). In many cases, it will go up -- it usually won't go down.