SINGLE-STAGE ISOLATED HIGH POWER FACTOR AC/DC CONVERTER WITH LEAKAGE INDUCTOR ENERGY RECOVERY FUNCTION

摘要

A single-stage isolated high power factor AC/DC converter with a leakage inductor energy recovery function includes a buck-boost circuit (230), for step-down or step-down a power supply; a transformer (Tb), electrically connected to the buck-boost circuit (230), for transforming the stepped-down or stepped-up power supply; a switch (S1), electrically connected to the buck-boost circuit (230); an input capacitor (Cin), electrically connected to the buck-boost circuit (230); and an output circuit (240), for outputting the power supply transformed by the transformer. When the switch is cut off, the buck-boost circuit provides an energy recovery path to return energy stored in a leakage inductor of the transformer to the input capacitor. The energy stored in the leakage inductor of the transformer in a flyback converter or a forward converter is returned to the input capacitor through the energy recovery path. The problem caused by the leakage inductor of the transformer is solved without using any additional element.