Investigation On An Interleaved Discontinuous-Current-Mode Single-Stage Power-Factor-Correction Converter

In the single-stage PFC (S~2PFC) converter, input current shaping, isolation and tightly regulated output are achieved in one step with only one switch and one control loop. Normally, the input power factor is not unity but the input harmonic current is small enough to meet the IEC regulation. As a consequence, in low power applications, S~2PFC scheme has been drawing great attention for its low cost and simple implementation. But typical S~2PFC topology suffers from some drawbacks, including high current ripple on the rectifier input, high bus capacitor voltage stress at high line and light load and low efficiency with the DCM operation of the Boost inductors.Based on the analysis of development of S~2PFC technique, a new interleaved discontinuous-current-mode S~2PFC converter has been researched in this paper. Reduced input current ripple is achieved with two interleaving inductors. Bulk-capacitor voltage feedback keeps the bus voltage within 450V in universal line applications. Half-bridge topology makes the voltage stress of the switch and the output response time reduced. On the other hand, enlarged capacity enlarges its application area.Firstly, after a brief introduction of research background and review of present PFC techniques, the research purpose and content are given.Secondly, S~2PFC technique is analyzed in detail, including the operation principle, topologies transition method and the drawbacks of the typical S~2PFC topology. Afterwards, the solutions to improve these drawbacks are introduced in category.Thirdly, the further investigation of a new topology of S~2PFC has been done. The operation principle of the circuit is analyzed and the relation between the main parameters is deduced. Based on the above work, a 24V/10A-output prototype is designed. Experiment results provided prove the performance: high efficiency, and bus voltage limited to 450V in universal line applications. As a result, we can draw the conclusion that this converter is cost-effective and practical.Finally, the summaries and the future work are given.