48-V Voltage Regulator Module With PCB Winding Matrix Transformer for Future Data Centers

Ahmed, Mohamed H.; Chao, Fei; Lee, Fred C.; Li, Qiang

doi:10.1109/tie.2017.2711519

Cited by 149 publications

(49 citation statements)

References 17 publications

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“…Vias must be used to connect all the parallel layers. If we directly borrow the design from [25], the termination vias will cut the primary windings [27]. It is possible place vias in a sparse manner so that there is some space for the primary current to flow through.…”

Section: Chapter 3 Transformer Design: Terminations and Viasmentioning

confidence: 99%

Optimal Design of Megahertz $LLC$ Converter for 48-V Bus Converter Application

Cai

Ahmed

et al. 2020

IEEE J. Emerg. Sel. Topics Power Electron.

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The intermediate bus architecture employing the 48V bus converter is one of the most popular power architecture. 48V to 12V bus converter has wide applications in telecommunications, networks, aerospace, and military, etc. However, today's state of the art products has low power rating or power density and becomes difficult to satisfy the demand of increasing power of the loads. To improve the current design, a GaN (Gallium Nitride) based two-stage solution is proposed for the bus converter. The first stage Buck converter regulates the 40V to 60V variable input to a fixed 36V bus voltage. The second stage LLC converter convert the 36V to 12V by a 3:1 transformer. The whole solution achieves the fixed frequency control. The thesis focus on the detail design and optimization of LLC converter, especially its transformer. To have high density and high efficiency, the transformer design becomes critical at MHz frequency. The matrix transformer concept is applied and a merged winding structure is used for flux cancellation, which effectively reduces the AC winding losses. A new fully interleaved termination and via design is proposed. It achieves significant reduction in loss and leakage flux. In addition, to study the current sharing of parallel winding layers, a 1-D analytic model is proposed and a symmetrical winding layer scheme is used to balance the current distribution. The hardware is built and tested. The proposed two-stage converter achieves the best performance compared to the current market. Intermediate bus architecture (IBA) has wide applications in telecommunication, server and computing, and military power supplies. The intermediate bus converter (IBC) is the key stage in the IBA, where the DC bus voltage from the front-end power supply is converted to a lower intermediate bus voltage. Traditional IBC suffers from bulky magnetic components including inductors and transformers.This work illustrates the design and implementation of a two-stage IBC, where the firststage Buck converter will provide regulation and the second stage LLC converter will provide isolation. Thanks to the soft-switching capability of LLC, the magnetic volume can be significantly reduced by raising the switching frequency of the converter. Therefore, planar magnetics can be used and placed directly inside of the printing circuit board (PCB), which allows for higher power densities and easy manufacturing of the magnetics and overall converter. However, as the frequency goes higher, the AC losses of the transformer caused by the eddy current, skin effect, and proximity effect become dominant. As a result, high-frequency transformer design becomes the key for the converter design. First, matrix transformer concept is applied to distribute the high current and reduce the conduction loss. Second, a novel merged winding structure is proposed for better transformer winding interleaving. Third, a new terminal structure of the transformer is proposed. Finally, the current sharing between parallel windings are modeled and studied. All the eff...

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Section: Chapter 3 Transformer Design: Terminations and Viasmentioning

confidence: 99%

Optimal Design of Megahertz $LLC$ Converter for 48-V Bus Converter Application

Cai

Ahmed

et al. 2020

IEEE J. Emerg. Sel. Topics Power Electron.

Self Cite

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“…Planar transformers and inductors are used in this research, and the magnetic core material is ML91S from Hitachi Metal, which has the lowest core loss density at the 1-MHz frequency among all available materials [46], [47]. Fig.…”

Section: B Magnetic Componentsmentioning

confidence: 99%

A 1-MHz Series Resonant DC–DC Converter With a Dual-Mode Rectifier for PV Microinverters

Shen

Wang

Shen

et al. 2019

IEEE Trans. Power Electron.

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The photovoltaic (PV) output voltage varies over a wide range depending on operating conditions. Thus, the PVconnected converters should be capable of handling a wide input voltage range while maintaining high efficiencies. This paper proposes a new series resonant dc-dc converter for PV microinverter applications. Compared with the conventional series resonant converter (SRC), a dual-mode rectifier (DMR) is configured on the secondary side, which enables a twofold voltage gain range for the proposed converter with a fixed-frequency phase-shift modulation scheme. The zero-voltage switching (ZVS) turn-on and zero-current switching (ZCS) turn-off can be achieved for active switches and diodes, thereby minimizing the switching losses. Moreover, a variable dc-link voltage control scheme is introduced to the proposed converter, leading to a further efficiency improvement and input-voltage-range extension. The operation principle and essential characteristics (e.g., voltage gain, soft-switching, and root-mean-square current) of the proposed converter are detailed in this paper, and the power loss modeling and design optimization of components are also presented. A 1-MHz 250-W converter prototype with an input voltage range of 17 V-43 V is built and tested to verify the feasibility of the proposed converter. Index terms-PV microinverter, dc-dc converter, series resonant converter, wide input voltage range, 1-MHz frequency.

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“…In order to achieving large inductance, an auxiliary core around primary windings and a low permeability layer between the primary and secondary are proposed in [43] and [42], respectively. For high output current situation, LLC converter with matrix transformer is proposed [75], [76]. The transformer consists of two cores, each of which integrates two matrix components.…”

Section: A Magnetic Integration Technologymentioning

confidence: 99%

Review of State-of-the-Art Integration Technologies in Power Electronic Systems

Wang¹

2017

CPSS TPEA

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48-V Voltage Regulator Module With PCB Winding Matrix Transformer for Future Data Centers

Cited by 149 publications

References 17 publications

Optimal Design of Megahertz $LLC$ Converter for 48-V Bus Converter Application

Optimal Design of Megahertz $LLC$ Converter for 48-V Bus Converter Application

A 1-MHz Series Resonant DC–DC Converter With a Dual-Mode Rectifier for PV Microinverters

Review of State-of-the-Art Integration Technologies in Power Electronic Systems

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