Boost PFC input line voltage drop at full load.

[Nick_PE]

In boost PFC, used 5KVA isolation transformer to provide 228-230Vrms input voltage.
While reaching full load(1.6KW), input line voltage drops to 219Vrms.
Can anyone please help to find reason behind this voltage dip?

 

[betwixt]

Are you saying the isolation transformer produces 228-230V RMS under low load but it drops to 219V under 1.6KW load? I'm not sure where the PFC comes into it.
It is normal for some voltage drop trough a transformer as its load increases, they are not perfect 'pass through' devices. The current is about 7.5 Amps so even the copper resistance in the transformer will cause some drop.

Brian.

 

[FvM]

A fully specified transformer has R% and X% respectively short circuit voltage specs, so you can calculate voltage drop for sinusoidal load current.

 

[cupoftea]

I would get your DMM and measure the pri and sec resistances.

 

[KlausST]

Hi,

if I remember right, then my line source impedance is about 1 Ohm .. so the line voltage drops about 1V fer every 1A a draw.

Klaus