The AC electric cars I have looked at use Async motors like the one you are building. Spped control is easy with a varibl frequency drive like the one you are building. Depends on how the motor is built as to the low rpm torque developed.
Synchronous motors with rotor windings to a controler can give good low rpm torque but then the overhead will increase, and more trouble with slip rings and all of that.
I knew I was going to confuse something. Your house like most I think have one transformer connected to one of the phases provided by the power company. The transformer has two output taps, both 120 volt. So both legs are on the same phase.
A typical 240 three phase will have one 240 leg and two 120 legs. ( some are 208/277 but that is another story) All coming from different transformers. Look at a power utility pole. If I place a meter across any to legs or phases it will read 240 volt. The water heater thing I mentioned is what messed this up .
The attached pict is a schematic of a water chiller. The compressor is 3 phase and the circulation pump is a standard 240 volt setup. The pump motor runs from two of the 3 phases making it a two phase motor. The same motor will also run on the 240 two leg single phase at your house.
But you can not feed a transformer with one phase and have three taps and run a 3 phase motor.
Originally Posted by mackrackit
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