How to select frequency converter to control a domestic refrigerator compressor

[newbieeng]

Hi guys. I want to control a variable speed compressor installed on a domestic refrigerator. But this is the first time I work on this so I really do not have any idea about this. How can I select a frequency converter to control a variable speed compressor? Which specifications, features I have to consider? Thanks in advance.

[aramis]

You must get information from the compressor manufacturer first.

For an AC motor you have to control both frequency and voltage. Many VFDs don’t produce sinusoidal waves so you have to install filters or all your electronic controls will go crazy.

It is not a good idea to use a frequency converter on a small compressor. It is better to buy a variable speed compressor directly.

You can get information on variable speed drives from here:
http://www.danfoss.com/Pacific/Products/Categories/Literature/RA/Electronic-Controls/Electronic-Controls-Speed-control-of-Compressors-Condensers-and-Fans/Variable-Speed-Drives/e46607a0-cacc-43e0-8841-98fa971ec28c.html

or here
http://www.emersonclimate.com/en-us/resources/faq/Pages/control_techniques_variable_speed_drives.aspx

But I’d suggest you use one of these:
http://www.danfoss.com/Pacific/Products/Categories/Literature/RA/Compressors/Direct-Current-Compressors/b44e7573-473b-4dba-90c2-431ffccf0b9c.html