The Symmetric Dual Inductor Hybrid (SDIH) Converter for Direct 48V-to-PoL Conversion

This work introduces the symmetric dual inductor hybrid (SDIH) dc-dc converter topology, which is suitable for large conversion ratios where regulation is required, such as direct 48 V to point-of-load (PoL) applications. A dickson-type switched capacitor network is used to effectively produce two interleaved PWM outputs with a greatly reduced voltage amplitude relative to the input voltage, allowing the subsequent magnetic volume to be reduced while retaining modest switching frequencies. Distinct from related variations, part count is significantly reduced while both even and odd order switched capacitor networks can be used with straightforward split-phase control; allowing either network type to achieve complete soft-charging of all flying capacitors. Additionally, charge flow is uniformly distributed through all elements, with equal capacitor and inductor values being preferred. Subsequently this topology is expected to simplify component selection, improve electrical and thermal performance, and reduce cost. Furthermore, analysis is presented that calculates precise phase durations without making small ripple assumptions, revealing up to a 75% timing error in cases where either inductor or capacitor ripple is ignored. Finally, a discrete prototype validates this analysis and demonstrates very high measured power densities of 1,029 W/in$^{3}$, 754 W/in$^{3}$, and 663 W/in$^{3}$ for 48 V input and regulated output voltages of 3 V, 2 V, and 1 V, respectively, while switching at a frequency of 750 kHz

An Interleaved 6-Level GaN Bidirectional Converter with an Active Energy Buffer for Level II Electric Vehicle Charging

On-board electric vehicle (EV) chargers provide ac to dc conversion capability to charge a high-voltage battery pack. As they are carried within a vehicle at all times, high efficiency and high power density are desirable traits for such a converter, in order to reduce the size, weight, and power loss of the system. Bidirectional capability is also desirable for an on-board charger to support vehicle-to-grid ancillary applications. This paper presents the implementation of a bidirectional single-phase ac-dc converter, converting between universal ac (120-240 VAC) and 400 VDC. Discussions of system architecture, control, mechanical design and assembly, and thermal management of an interleaved 6-level flying capacitor multilevel (FCML) power factor correction (PFC) stage with a twice-line-frequency series-stacked buffer (SSB) stage are included. Experimental results demonstrating dc-ac inverter operations at the kilowatt scale are provided. A peak efficiency exceeding 99% is observed, and a maximum power of 6.1 kW is tested