How to convert 400V into 240V?

[366cobra]

How to convert 400V AC into 240V AC?

hi,

what would be the easiest/cheapest way to convert AC 400V, 6A, 100Hz into AC 240V, 50Hz?
i probably cannot use a transformer, as the starting voltage - up to 400V - fluctuates.
depending on speed of the shaft of the generator, the voltage may vary between 350V and 400V.
i am using an old AC 240V, 1A motor from a washing machine, which is being used as a generator.

schematics would be great.

 

[atripathi]

Do you need 240vAC or DC, if AC, what frequency & wave shape, how much of THD you can tolerate?

 

[kak111]

If your generator is normal AC induction motor ( 240V / 400V)
use star connection
Star-point is neutral and coils other ends are L1, L2 and L3 (220Vac to neutral)

 

[366cobra]

did not explain it too well.
sorry, my bad.

i would like to convert whatever voltage is coming out of an old motor into 240V mains at 50Hz.
the voltage varies, as the speed/motor changes.
one old motor is from a washing machine, rated at 240V and 1A.
at the speed that i have got it going at the moment, it produces ~370V and 3.7A.
i do not know the Hz it generates.
i will also try out some other motors, 2 and 3 phase, so the converter should be able to handle more voltage and ampere into what house appliances use.

to convert a motor into a generator, i connect a cap between the outlet.

the conversion should be done on a low budget, as it is just for experiments.

thanks

 

[366cobra]

took another measurement today and the generator produced AC 364V, 3.6A at 101.3Hz

 

[Raza]

366,
If you rotate motor and higher speed the frequency won't be 50Hz. You can not run the generator at random to get 50Hz, as the shaft speed and number of pole are directly proportional to frequency. See here the example for more clarification.
AC Motor Speed Controller
Getting more voltage and current will vary the frequency, it is ok if you are not concerned on Frequency of the generator.