Hi,
First why need of pfc,
1.To reduce the harmonics frequency and delivered the fundamental frequency to load input.harmonics frequencies generaly doesn't effect the load, its effect the mounting socket(like heating),circuit breakers,
For examble one CB rating is 15A,and its normal working current is 12A(80% of the full load) without pfc powersupply,s power factor is 0.65 normaly and its efficiency is .85.so the total power deliver to the load is 230*12*.65= 1794w.when using the pfc the power factor has improved to upto .99.so the total power cosumable is 230*12*.99=2732.4w. total difference is 938w.
two types of pfc is there.1.passive pfc .this type of pfc is lesser coast and acive 0.8-0.9.its required some inductace(L)
2.active pfc>this type of pfc required higher coast,switching ic's,switches, x capEtc.this type we can acive upto 0.99.
QUOTE(shaha @ Sep 4 2006, 02:39 PM)

Hello. I am new to this forum and first I want to excuse me for my probably bad english.
I am working on a device for automatic PFC (using just capacitors, not filters). My job in this project concerns generally weak current parts (microcontroller, indications, control, software). But now I have to read a lot of information about PFC. Unfortunatelly I found in this forum almost only one thing - Everybody repeats and explains that adding capacitors will not change the electricity bill. Well

.
Could somebody give me links to some more specialized and detailed (designer's) information. For example at this moment I am looking for information about capacitors switching /Tips and tricks, possible problems, ways of realization and algorithms/.