On the Elimination of Pulsed Output Current in Z-loaded Chargers/Rectifiers

As proven in literature, the Z-loaded rectifier is an alternative topology for PFC applications requiring wide output voltage controllability. The main advantage of the Z-rectifier is the availability of two control signals allowing buck-boost operation. This raises the possibility of regarding the Z-rectifier as a novel single-stage PFC converter with ripple-less output regulation, whereby one control signal is used for input current shaping, while the other for reduction of pulsating output current in charger applications. This paper qualifies the advantages over the typical 2-stage approach and describes how decoupling the two control signals and forcing one of them to be placed within its useful range can accomplish such a scheme. Simulations are presented to confirm the mathematical derivations.