Simple Motor Control Application?

DC motor is best bet for simple control. then brushless, then AC motor.

if you simply control speed, buy a measuring speed generator which offer speed feedback, then control power supply,

enough.

From a mechanical standpoint, you can look at a variable pulley set-up.

If you want to go electrical control, then an Variable Frequency Drive is the way to go. Some go as low as 150 USD. However, most VFD's are for 3-phase motors (tried and tested), but there are some for 1-phase (never tried this though, just saw it in a website).

There are also DC motor alternatives, but I think for that HP range you're better off looking at golf cart parts or hobby electric vehicle manufacturers.

<All I need to do is control speed. Set rpm and let it run>

<Does anyone have a feeling >

<best suited to this requirement?>

<complicated drive technology, etc., but they have all been overkill.>

Cris96, let us discuss your needs:

You want to "Just set rpm "and "Let it Run". Do you mean- you want a feedback control loop to hold RPM rock steady even when voltage ,frequency load,torque -needs may keep varying?And such control loop is needed(by you).

If that is what you want-complicated drive technology is not overkill .

Yes we all have a feeling for you!

best suited to this requirement?

Pray what is your requirement-Redefine.

u could simply use a synchronous machine with permanent magnets that u can find on www.maxonmotors.com in EC-motors,or even ECmax brushless motors.

if u need any help send me a message by mail at anthonybas@hotmail.com

Dear Sir

You may Ac drive tocontrol the speed since DC drive is bit complicated & also have tobe maintained properly

Rgds

S.Purushotham

Probably the simplest approach would be a synchronous motor, as its speed is determined by the A.C. line frequency. However, if the load torque varies considerably over time, you may need to implement tighter speed controls which, of course, implies greater complexity and expense. Alternatively, use a larger synchronous motor with sufficient excess H.P. to supply additional torque when needed, without incurring excessive droop. You may also wish to add a flywheel to the motor (possibly to a smaller motor that meets your H.P. needs, with a bit of margin) if variations in the load torque are more of a brief, transient nature.

Calculating Synchronous Speed:

AC motors are considered constant-speed motors. This is because the synchronous speed of an induction motor is based on the supply frequency and the number of poles in the motor winding. Motors designed for 60 Hz service have synchronous speeds of 3600, 1800, 1200, 900, 720, 600, 514, and 450 rpm.

To calculate synchronous speed of an induction motor, apply this formula:

RPM_syn = 120 x f/Np

RPM_syn = synchronous speed (in rpm)
f = supply frequency in Hz
N_p = number of motor poles

Example: What is the synchronous speed of a four-pole motor operating at 50 Hz?

RPM_syn = 120 x f/Np
RPM_syn = 120 x 50/4
RPM_syn = 6000/4

RPM_syn = 1500 rpm

(Motor-speed formulae courtesy of Electrician's Toolbox)

I would suggest that you look into a frequency drive. They've come a long way in their application and cost.