Is it possible to generate AC power by powering an alternator using a DC motor? If you think about it is much easier and better sine wave than a circuit?
Why isn't it used then? What are the drawbacks?
Also, will the loss be greater? I am estimating a 20%-30% loss (even less with better quality equipment ) but I don't really know how to calculate it nor have the equipment need for testing
Best Answer
Yes, this method (rotary converter, generically) has been used to create AC from DC and DC from AC (and AC of a different frequency or number of phases from AC). Sometimes the generator or alternator was combined with the motor in one machine, sometimes distinct motor-generator pairs were used.
A motor driven alternator will not necessarily have a beautiful textbook sine wave- the alternator design and the loading will also affect the waveform.
Obvious disadvantages include weight, cost, lifetime of the bearings, audible noise and vibration. Efficiency might be comparable to solid state in some cases so I would not list that as a disadvantage.
This is pretty much a ship that has sailed- solid-state solutions are almost always better these days. Hobbyists sometimes make rotary phase converters using scrap 3-phase motors (because you can buy them for almost nothing), but manufacturers use AC->DC->AC variable frequency converters made with IGBTs or MOSFETs.