Nov 2026· IEEE transactions on power electronics· Vol 41, pp. 18964-18975· 0 citations· 29 references
Abstract
This article proposes a high-power-density flux-split coupled-transformer voltage regulator (FS-CTVR) with improved dynamic response for 48 V data center power supplies. The topology resolves the large winding loss and insufficient dynamic performance of convenitional current Doubler rectifier (CDR) converters. A magnetically integrated transformer with primary flux splitting and secondary parallel current sharing is developed to achieve a high turns ratio, reduce winding footprint and current stress, and mitigate winding losses. Additional PCB winding layers form a common coupling loop for multiphase CDR transformers, which reduces transient output inductance and improves dynamic response. Comprehensive analysis, design and performance evaluation of the FS-CTVR are presented. A two-module parallel prototype (54 V input, 0.9 V output) is built and tested. Each module delivers 150 A full-load current, 88.6% full-load efficiency and 1687 W/in3 power density, with a dynamic voltage fluctuation of 88 mV. Experimental results validate the feasibility and superior performance of the proposed topology.
This article introduces a novel ultra-high voltage gain DC-DC converter with a low component count, designed for renewable energy applications. In the presented topology, a three-winding coupled-inductor (TWCI) and a switched-capacitor network are embedded within a classic quadratic boost converter. This arrangement yields high voltage gain, ensures continuous low-ripple input current, and preserves a common ground between the source and the load. Due to its trans-inverse feature, the circuit achieves ultra-high voltage gain even with a very low turns ratio in the TWCI. The topology also features current sharing between the TWCI and the main power switch, which significantly reduces power losses in the main power switch and coupled-inductor device. To limit voltage stresses on the active switches, the circuit integrates two passive regenerative clamp circuits, with the switches themselves operated using simultaneous switching patterns. The paper provides detailed steady-state analysis, power loss calculations, comparative evaluation, and design considerations. Finally, a laboratory prototype rated at 200 W has been implemented to verify the theoretical analysis, achieving a very high voltage conversion from 20 V input to 400 V output.
By integrating a three-winding coupled inductor (TWCI) with voltage multiplier cells, this study proposes a quadratic DC-DC converter that achieves ultra-high voltage gain while maintaining continuous input current and a common ground. The proposed coupled-inductor topology is specifically engineered to minimize both voltage and current stresses across all circuit components, thereby enhancing overall performance and enabling potential cost reductions. Enhanced design flexibility is a key feature of the proposed configuration, particularly because the secondary winding of the TWCI operates in a semi-trans-inverse manner, allowing high voltage gains to be realized even with a very low turns ratio. Regenerative passive clamp circuits are incorporated to recover the leakage energy of the TWCI and to limit voltage stresses on the active switches, which are driven with simultaneous switching patterns. The converter's vertical structure further alleviates semiconductor voltage stress, while intrinsic current sharing between the TWCI and the input inductor substantially reduces power dissipation in the main power components. Additionally, turn-off switching losses of both active switches are minimized via a quasi-resonant cell. The paper presents a comprehensive steady-state analysis, detailed power loss evaluation, a comparative study with existing topologies, and key design guidelines. All theoretical contributions are conclusively validated through experimental results obtained from a 200 W hardware prototype, converting a 25 V input to a 400 V output.
Mohammed Jawad Kadhim, M. Moazzami, G. Shahgholian et al.· Scientific Reports· 0 citations
High-frequency operation is a well-established strategy for miniaturizing power converters, but eddy-current losses in magnetics thermally limit its effectiveness in high-power converters. Interleaved windings, which reduce the magnetic fields around the windings, have therefore become standard practice. However, at high frequency, the current crowds to a single conductor surface, limiting the optimal copper thickness and causing excessive winding losses. This paper introduces field-balanced windings (FBW), a family of windings that establish balanced magnetic fields that are both reduced and symmetric about the center of the conductors, leading to current flow on both surfaces of the conductor (“double-sided conduction”). This yields a series of benefits for the transformer design, reducing its footprint, core loss, winding loss, parasitic capacitance, and leakage inductance. A Pareto-optimization case study shows that the FBW transformer design is up to 39% more compact than its interleaved counterpart. Three novel, scalable methods for realizing field-balanced windings are introduced and validated, supported by design guidelines for high-frequency transformers. The concept is demonstrated in two 400/800 V LLC-resonant onboard-charger DC-DC converters: a fixed-frequency 800 kHz DCX converter that delivers 7.4 kW at 97.7 % peak efficiency and 13.5 kW/L, and a frequency-regulated converter that covers the full 720–920 V battery range over 380–800 kHz at 98.4 % peak efficiency and 11.2 kW/L. Among reported transformers, these prototypes achieve the highest operating frequency at the presented power level and realize state-of-the-art surface power density.
H. Wouters, Wout Vanderwegen, Thomas Jochmans et al.· IEEE Open Journal of Power E...· 0 citations
A DC–DC power conversion topology based on a single controlled switch and high voltage elevation is developed, employing magnetic energy transfer and an integrated passive clamp to mitigate the voltage stress on the MOSFET. Operating at a duty cycle of 41.7%, the converter achieves an output–input voltage ratio of 16.67, stepping up from 24 V to 400 V. The proposed topology overcomes key limitations of conventional converters, including high losses at large duty cycles and excessive component counts in cascaded architectures. Comprehensive steady-state operation, voltage and current stress evaluation, power loss assessment, and passive component design are analytically investigated. Comparative evaluation with existing high step-up topologies and simulation validation are also presented. Simulation results under a 300 W output power condition demonstrate a peak efficiency of 95.44% and low output voltage ripple. The outcomes support the analytical framework and indicate the suitability of the proposed converter for real-world applications requiring stable high-voltage DC conversion from low-voltage sources.
Thai Anh Au Tran, Xuan Khanh Ho, Hoai Khanh Ly Le· E3S Web of Conferences· 0 citations
High-efficiency and high-power-density point-of-load (POL) converters are critical for data center power supplies. Although hybrid resonant switched-capacitor (ReSC) converters can substantially reduce the volume of passive components, they often suffer from severe efficiency degradation when the switching frequency mismatches the resonant frequency due to component tolerances. To address this challenge, this paper proposes a parameter-mismatch insensitive cascaded POL converter by integrating a BUCK stage with a cascaded voltage divider (CVD). By introducing an auxiliary resonant branch, a multi-resonant operation is established, enabling the residual inductor energy caused by component variations to be transferred to the output during the dead time with virtually eliminated hard-switching losses. Consequently, precise matching between the switching frequency and the resonant frequency is no longer mandatory. A 12 V-to-1 V/30 A GaN-based prototype was developed to validate the theoretical analysis. Experimental results demonstrate that the proposed converter maintains high efficiency under a ±10% component variation and achieves robust voltage regulation and fast transient response, making it highly suitable for high-current data center applications.
Dejun Ba, Yihe Wang, Qi Cao et al.· Energies· 0 citations
This paper presents a high-step-up DC-DC converter suitable for low-voltage source applications, such as renewable energy systems. The proposed topology integrates a two-stage structure, two coupled inductors with dual windings, and a voltage lift technique to achieve high voltage gain, continuous input current, and reduced semiconductor device voltage stress. The converter features a common ground between the input and output sides, which facilitates system integration and control. The input current is divided between the two coupled inductors, thereby limiting losses in the input-side components. Steady-state analysis of the converter was performed to determine the voltage gain, voltage stress, and component currents. Relationships relevant to the converter's design have been presented to facilitate its operation under the required conditions. Additionally, small-signal analysis was conducted to support the controller design, and the corresponding transfer functions were derived. The converter's power losses have also been calculated. Afterward, a comparison is presented between this structure and other designs in the literature to identify its advantages and disadvantages. To validate the theoretical analysis and practical feasibility, a 100-W prototype with a 200-V output voltage was implemented. The experimental results show good agreement with the theoretical predictions.
Iman Soltani, Saeed Sharifi Jeze, G. Molaeimanesh et al.· IEEE Open Journal of Power E...· 0 citations
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