Power factor correction via passivity-based adaptive controller using buck converter operating in continuous mode

A passivity based control scheme is applied to a buck converter operating as an active power factor corrector. The converter is modeled via an Euler-Lagrange (energy) approach and two control laws are derived from this non linear model: a direct control (using the voltage in the capacitor) and an indirect control (via the current in the inductance current). The resistive load impedance is estimated using an adaptive approach. There is no need to consider the small signal condition as in the case of linearized models. The control laws satisfy a wide range of operation of the converter.