Help me about pfc circuit

[kidmaster08]

I don't understand about function of a pfc circuit. and howto caculate passive pfc and active pfc. please help me

 

[chuckey]

Loads on the mains must not be too inductive because this upsets the generators, so the out of phase inductive current is balanced by the identical capacitive current. So outside of the building there is no inductive current to be measured.
So work out what is needed, you need to find the inductive current, based on the total (measured) current and the power factor. Then calculate what capacitive reactance you need to get this current. Thats it.
Active PFC correction is based on switching a capacitive load in and out very rapidly via a PWM system, so as to get the effect of a variable capacitor to the mains. The system obviously try to balance the current to cancel out the reactive components.
Frank

 

[kidmaster08]

I DONT UNDERSTAND MEAN OF WORK 'THE MAINS'. I THINK THEM AS GENERATOR MAKING OFF LINE VOLTAGE.
I 'VE BEEN TO KNOW pfc USED TO MAKING IN FASE BETWEEN CURREN AND VOLTAGE AT INPUT OF RECTIFIERS.
REALLY THAT, PLEASE. THANK YOU VERY MUCH FOR ATTENTION.