# Generator Equation

1. Dec 11, 2005

### mtanti

Does anyone know of an equation which relates RPM with power in a generator? It has to be for a general generator!

2. Dec 12, 2005

### toxique

I am not sure (im still a newbe ), but lets work in senoidal regime:
Voltage v(t) = V . sin(wt+p)
w (omega) is in radians, so you could make w an equivalent to RPM:
1 RPM = 1 radian = 2*PI
Of curse, you will also need current and impedances for a deep analysis, but you can get the idea (P = (V^2)/Z)
I hope this is OK, sorry everyone if this is screwed up.

3. Dec 12, 2005

### dlgoff

For alternating current (A.C.), the RPM of the generator determines the frequency of its output. In the U.S., power companies try to keep the frequency at 60Hz. When the load on the systems increases, the frequency tends to lower, so more power (steam flow through the turbin) is needed. The opposite happens when the load decreases.

Regards
Don

4. Dec 30, 2005

### phantom_photon

Well,

output power = input power - losses = wT - losses = (2*pi/60)*RPM*T -losses.

That's the most general equation I can think of without getting into reaction torque, inertia, etc.