Design of power factor corrector for the off-line isolated buck/boost converter by a voltage-follower technique

Abstract

A voltage-follower controller (VFC) formed by the usual PWM controller is proposed that improves the power factor of the isolated buck/boost (flyback) power converter in the discontinuous conduction mode (DCM). The presented VFC can adaptively control the line current in phase with the input line voltage to achieve nearly unity power factor under the full-load condition. An isolated 50 W buck/boost power converter with VFC in DCM is realized that improves the power factor to 0.994.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>