Frequency and Voltage change for elektromotor

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Lorcan

New Member
Hey All,


could use some help with finding/designingg a circuit that gives me the possibilities to run an elektromotor with different voltage and frequencies.
this is a 3PH elektromotor that should be run in a Y configuration on at
110-115V @ 50 to 60Hz,
220-230V @ 100 to 120Hz,
340-360V @ 150 to 180Hz and as last
460-480V @ 200 to 240Hz

Have thought about using a transformer and a computer with relay, but prefer an independent system .
For the first 110-115V @ 50-60Hz, have already a solution, have this heavy transformer that transforms 220-230V to 110-115V, since the electric grid works on 50-60Hz, that already fixed.

But what about the others?
any advice?


kind regards,
Lorcan
 
Is your stock motor designed to run at 240 Hz 480 VAC input?

If it was designed for normal 50 - 60 Hz input running it at 4 - 5 times it stock speed could cause the rotor to literally fly apart.
 
Not only that, but the hysteresis losses of the magnetic steel at 240Hz would cause it to overheat tremendously.

For variable frequency drives, the highest speed is at nominal frequency and voltage. For example 1800RPM @ 240V, 60Hz
Then you start varying the voltage and frequency DOWNWARDS, i.e.
900RPM @ 120V, 30Hz
450 RPM @ 60V, 15Hz
and so on.

Varying the voltage is a piece of cake, but varying the frequency...that would be very complicated for a begginer. This is what variable frequency drives do. Google the term, there are many commercial units availble.
Its size and cost will depend on your motor's power ratings.
 
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