Dc short shunt compound generator problem

Thread Starter


Joined Mar 5, 2007
I'm running through an example and trying to find out what the losses would be in the shunt field.

See attached image for the circuit diagram.

Anyhow I've figured out the following:
IL = 32 A

Vf = 259.6 V

If = 2.6 A

Ia = 34.6 A

E= 276.9V

The efficiency to be : 76.92 %

The iron,friction and windage losses to be : 819.26 W

What I'm a bit confused about is that I've found that the loss in the shunt field is equal to If * V which gives me 650 W.

However in my another notes it says that the loss in the shunt is equal to If^2 * Rf which gives me 676 W.

However which one would resemble the losses in the shunt field? Or have I gone completely the wrong way about this?

Many thanks,