Not quite. The power transmitted is a function of the supplied voltage and
the loading (and current). Lets not go into power factor here. The frequency
effectively determines the distance you can transmit. Higher frequencies
allow for smaller transformers and generators (planes and ships use 400 Hz
for this reason), while lower frequency is good for transmission distance -
lower frequency, longer distance. This is due to the impedance (resistance,
inductive reactance and capacitive reactance) of the transmission line.
That's why they used 25 Hz for generation for industry at the turn of the
century. With the invention of synchronous condensers the power line effect
at 60 Hz could be compensated for, so 25 Hz generation development stopped.
And it means there was only one set of power lines everywhere. Transforming
voltages are easy, frequency transformation is a real pain.
In relality there is little difference between 50 and 60 Hz. The
transformers are slightly smaller for 60 Hz. But 50 Hz has a time base of 20
milliseconds instead of 16.666666666666666667. This makes life so much
easier! Particularly with disturbance recorders. 50 Hz gives lower speeds on
the generators for the same number of poles which is less mechanical stress.
Basically North America uses 60 Hz because Nikola Tesla believed it was the
optimum point between size, efficiency and transmission.
Foxy
----- Original Message ----- >
> This is different in the states where 60 Hz has affected the way they us
> electricity. They use 110 volt for normalloads and 220 volts for high
power
> loads. For a certain load of power, less volts requires more current. More
> current requires more copper. And this cost a lot. I'm a little grey on
the
> US distibution system, but I recall that they get three wires to their
> house - two 110 volts to neutral and 220 volts between the two 110 volt
> wires. Personally, I think they can't accept that they should have gone
240
> volts 50 Hz!
>
Well you didn't mention that they use 60 Hz instead of 50Hz for exactly that
reason ! I.e. higher frequency enables more power at lower voltage without
the need for higher current or thicker wires.
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