An improved control strategy of standard power factor preregulators (P
FP's) is proposed, which allows fast output voltage response while mai
ntaining a high power factor. This is obtained by compensating for the
intrinsic low-frequency output voltage ripple, thus allowing a higher
bandwidth of the output voltage control loop. This method does not re
quire additional sensing, but only a multiplier and simple analog circ
uitry, and it works well with a universal input voltage range. Experim
ental tests on a boost converter with average current control confirm
the validity of the approach.