Answer to Question #91561 in Electrical Engineering for Shawn Dickson

Question

Find speed of generator when it has 7.5kw, 20 Amps, B = 0.8w/m2, length = 150mm, diameter 200mm, there are 600 conductors at 65 % below the pole.

I just don't understand the 65% below the pole. Does it relate to phase angle or power factor somehow?

Answer 1

The induced voltage of a generator can be calculated as

$$E=\frac{P}{I}=\omega\Phi\space\text{sin}(\omega t),$$

where $\omega$ - its speed, $\Phi$ - its magnetic flux. I've never heard about percentage of conductors below the pole. Even when designed a generator. To me it feels like it points to the fact that the generator has implicit poles. From the expression above it can be possible to calculate the speed if you also clarify what is B measured in w/meter squared.