Jim Coate wrote:
> Jim Phillips wrote:
> > (I was there with my AC powered tractor)
>
> OK, I'll bite... "AC powered tractor" as in a battery electric tractor
> with an AC motor/controller? If so, I'd love to know a little more about
> it, and/or see a picture (or link to a web site if you have it up
> anywhere). Thanks.
I'd love to talk about it! You're correct on all accounts. I
have talked a little bit about it here, but I'm a terrible typist
and it is slow going.
The motor is a standard 2 hp, 220/440 volt AC induction motor.
The motor rewinder found it in his junk box because a bearing
failed and the motor burned up. I had him rewind it with 1/10
the number of turns (cost $250). That made it 22/44 volt motor.
It is used in the 44 volt configuration.
The controller is variable frequency/ variable voltage PWM. Max
frequency is about 150 Hz. Battery voltage is 48 volts (yes, a
bit high for the application) The controller is simple slip
control, not vector or anything and no processor. I use some 100
amp 70 volt FETs as the drive.
I am very happy with the performance. The control is very smooth
and easy to operate. I can spin the tires in high gear on dry
pavement and it will go about as fast as is safe. Haven't gotten
the mower finished so I mostly use it to tow cars :-)
There is a lot to say about it (too much for an email), I
purposely did things that no one else has done, just to be
different. I am working on my web site (also send it to the
album) should be ready in a week or two.
Jim Phillips
