부산대학교 도서관

The 48 V voltage regulator modules are crucial for 48 V data center power architecture. A quasi-parallel topology, the Sigma converter, has been proposed as a 48 V single-stage solution offering high efficiency and high power density. However, the complexity and distinctiveness of the Sigma converter's quasi-parallel structure render its control mechanism a crucial aspect that requires detailed analysis, especially given the fast load transient response requirements. In this article, the small-signal analysis of the Sigma converter is performed under different control methods, including voltage-mode control, current-mode control, and enhanced V 2 control. The small-signal performances of these control methods are compared, leading to the selection of enhanced V 2 control. Subsequently, an adaptive voltage position (AVP) design of the Sigma converter is proposed based on enhanced V 2 control, along with guidelines and limitations for stabilizing the converter and improving performance. Finally, the AVP function and load transient performance are verified by simulation and experimental results.