variable speed drive (single-phase Induction Motor)

[anslem321]

Can anyone help me out on how to design a power electronic drive for a single-phase Induction motor or any references available on this topic? I only managed to seek out references on 3-phase IM speed control. Thanks and hope to hear from anyone soon...;p;

[jraef]

Unlike with 3 phase motors, there are many different types of 1 phase motors, most of which are NOT suitable for using a PWM variable speed drive on them. The ones that are have limited applications that can use them. If this is for your own use, you are probably better off buying one that already exists, the cost of making one from scratch would be prohibitive. The only one's I have heard of are from Invertek (marketed by several other brand names, but they are all made by Invertek), http://www.pepperneck.com/invertek_dev/pro...=9&top=products,

and Varidigm http://www.varidigm.com/pdf/Approved%20Fin...%2015-1003A.pdf

Both of those only work on PSC (Permanent Split capacitor) motors, which are low torque designs suitable for pumps and fans, but not much else. They can technically be used on Shaded Pole motors as well, but then again, those can be controlled with simpler rheostats anyway so it doesn't make much sense. All other 1 phase motor designs use a speed switch and starting capacitors, making them unsuitable for use in transistorized drives.

 

If you are thinking about entering the business, I would do some serious investigation as to why. The fact that you don't already know all this shows that maybe it would not be a good idea. It is a limited market and from what I have heard, neither of these two companies sell a lot of these drives, they both have other products that keep them in business.

[marke]

Hello anslem321

 

There are some single phase motors that are designed for high slip. These motors are generally a integral part of a fan assembly and can be speed controlled by variable voltage only. This is not true for standard induction motors.

 

Best regards,