AC to Ac Power factor Correction........need help

[abcsantosh]

    Hi all, I need to design a AC to Ac Power factor Correction circuit, which takes 220V ac input, restores power factor and puts corrected 220V ac output. The design must have corrected pfc ac output with voltage regulation and over current protection. Like conventional smps ac to dc pfc boost circuit has.
   
    I have ample experience of building ac to dc pfc circuits up to 2kW. But I never build the ac to ac pfc circuit. give me the clue, ideas for topology, costs and what is the best fit solution etc. refer any application notes if available. I would like to build it in SMPS way.
   
    Application spec. are wide input range ac(Universal input ac or 180Vac to 265Vac) and 220V ac output for 100W

have a nice day....
     

[Kabron]

The device you're going to build is a double conversion UPS without batteries. See UPS reference design in Microchip's appnotes.

[abcsantosh]

    Hi, Thanks for reply. I read the Picref-1 documents. It seems it is going to cost me a lot in price and size.
    Is there any other method to obtain direct AC pfc output, without converting it into dc and then again convert it into ac ?

[Kabron]

Depending of load nature (C or L) it migh be Capacitor/Inductor switchable banks. But it'll be more expensive than double conversion and non implemented for switch mode loads.

Posted on: 09 July 2009, 17:10:31 - Automerged
P.S. frequency converter for AC motor might be a solution if equipped with PFC.

[ALLPIC]

there is one anather mathode is to add C according to L load. That is called as PFC pannel where the controller is calculating capacitive KVAR and then adding that capacitor.

The simplest methode is take fan or motor capacitor and connect to load you will see power factor is improveing.

The trick is calulating current powerfactor and required KVAR then by switching contactor or relay you can add or remove Capacitor. This is one of methode used in lot of big industries for maintaing PF. Because Online UPS can't be done more than 600A so this methode is used there

I think this will help you

regards

[Jehan]

Direct conversion from AC-AC can be accomplished by Matrix converters, but it is a vey difficult piece of technology

[Orcino Borges]

Look IR1150

       Orcino

[Walkura]

On the point of AC-AC converters i have a article but this is meanth for voltage regulation (ac-ac)
Powerfactor isn't mentioned in this paper but it might bring you to idea's .
http://rapidshare.com/files/236066661/ac-ac-buck.pdf
Just have a look maybe this setup can be usefull for ac-ac conversion .
From what i remember either Pressman or Marty Brown also mentioned ac generation setups in their switchmode books .
(i uploaded those last year to the ebooks section)
In itself i think the ac-ac setup from this paper is nice ,for a 100 Watt there shouldnt be to much trouble .

Good luck and be carefull .