Some Control Aspects of Single-Phase Power Converters with an Active Pulsating Power Buffer

Single-phase power converters with an active pulsating power buffer (APPB) have become a hot research topic in the recent decade. Unlike their conventional counterparts that utilize bulky electrolytic capacitors (E-caps) to stabilize the dc output voltage, this emerging class of converter employs an APPB that allows large voltage fluctuation to handle the inherent double-line-frequency pulsating power. As a result, the required capacitance can be greatly reduced and thus the E-caps can be replaced by more reliable film/ceramic capacitors. Both power density and reliability of the power converter can potentially be improved with this new technology. In existing works, more attention has been given to the topology of this new type of converter than to the controller design. This tutorial paper aims to give a brief introduction of this APPB technology. Particularly, the focus is given to the control aspect, including some nonlinear control and estimation techniques.