ارائه مبدل‌هاي DC-DC بسياركاهنده هايبريد سه مسيره با چگالي جريان بالا و قابليت استفاده از سلف‌هاي با DCR بزرگ

With the rapid expansion of electronic systems an‎d the increasing deman‎d for low-voltage, high-current power supplies, high step-down DC–DC converters have become an integral component of point-of-load (POL) power supply systems. Direct conversion from high input voltages to low output voltage levels using a conventional buck converter requires operation at an extremely low duty cycle, which is associated with several limitations, including increased power losses, higher current stress on components, an‎d difficulties in achieving high power density. Moreover, in the buck topology, the entire load current flows through the inductor; therefore, in high-current applications, the conduction losses of the magnetic components can account for a significant portion of the total converter losses. Hybrid converters, by combining capacitive an‎d inductive networks an‎d providing parallel power-transfer paths, offer an effective approach to reducing the dependence of power transfer on the inductive path while achieving lower voltage conversion ratios. This thesis proposes a three-path hybrid high step-down DC–DC converter. In the proposed topology, power transfer is distributed between capacitive an‎d inductive paths, thereby reducing the current flowing through the magnetic components relative to the load current. This feature not only reduces the conduction losses of the inductors but also enables the use of smaller magnetic components. Furthermore, by providing a low voltage conversion ratio, the proposed topology enables direct conversion from a 48 V input to a 1 V output without requiring an extremely low duty cycle. In this study, the operating modes of the converter are analyzed, an‎d analytical expressions for the voltage conversion ratio, inductor currents, voltage an‎d current stresses of the switches, an‎d component losses are derived. Additionally, the switching conditions of the converter enable zero-voltage switching (ZVS) turn-on for several switches, thereby reducing a portion of the switching losses. The performance of the proposed converter is eva‎luated through simulations an‎d experimental results, confirming the validity of the theoretical analysis an‎d the proper operation of the proposed topology. Simulation results for a 48 V-to-1 V conversion at an output current of 5 A demonstrate a peak efficiency of approximately 92%. Furthermore, a comparison of the proposed topology with several high step-down converters reported in the literature demonstrates its capability to reduce the current stress on magnetic components, appropriately distribute stresses among the components, an‎d achieve a low voltage conversion ratio. Finally, complementary operating modes are derived an‎d investigated by modifying the switching configuration of the original topology. These modes provide different voltage conversion characteristics without requiring any modification to the basic circuit topology.

حسين فرزانه فرد , رسول دهقاني

احسان اديب , امين مشكات

اصغر غلامي , نسرين رضايي حسين آبادي