Analysis and Design of a LowStress BuckBoost Converter in UniversalInput PFC Application.pdf

320 IEEE TRANSACTIONS ON POWER ELECTRONICS, VOL. 21, NO. 2, MARCH 2006 Analysis and Design of a Low-Stress Buck-Boost Converter in Universal-Input PFC Applications ´ Jingquan Chen, Member, IEEE, Dragan Maksimovic, Member, IEEE, and Robert W. Erickson, Fellow, IEEE Abstract— In converters for power-factor-correction (PFC), the increased component stresses and component sizes compared universal-input capability, i.e., the ability to operate from any to the boost converter [2]–[6]. ac line voltage world-wide, comes with a heavy penalty in terms In general, if their conversion characteristics meet the of component stresses and losses, and with restrictions on the dc output voltage. In this paper, we propose a new two-switch input/output specifications, the boost converter (for voltage topology, boost-interleaved buck-boost (BoIBB) converter, which step-up) or the buck converter (for voltage step-down) feature can offer significant performance improvements over single-switch the smallest component stresses. This is a result of the direct buck-boost converters (including flyback, SEPIC, or Cuk topolo- energy transfer path from the input to the output in one of the gies) or other two-switch buck-boost converters in universal-input switching subintervals in these two converter topologies. The PFC applications. The paper presents an analysis of the converter operation and component stresses, as well as design guidelines. boost and the buck converters require the minimum indirect High efficiency (over 93%) throughout the universal-input ac line energy delivery and therefore have the mi