Latest Advances of LLC Converters in High Current, Fast Dynamic Response, and Wide Voltage Range Applications

Chen, Yang; Liu, Yanfei

doi:10.24295/cpsstpea.2017.00007

Cited by 24 publications

(5 citation statements)

References 36 publications

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“…The maximum voltage gain G max can be determined according to the input voltage, output voltage, and transformer turns ratio. (19) In order to satisfy the voltage gain requirement during the whole operation range, the converter should achieve the maximum gain under the worst case, that is, when input voltage reaches its minimum value, and the output power reaches its maximum value. From (8), the maximum voltage gain of the magnetically controlled LLC resonant converter can be expressed as (20) Based on (21), the relationship between the maximum voltage gain M max and the magnetizing inductor value L m can be obtained as shown in Fig.…”

Section: Design Methodologymentioning

confidence: 99%

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Comprehensive Analysis and Design of LLC Resonant Converter With Magnetic Control

Wei¹,

Luo²,

Mantooth³

2019

CPSS TPEA

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Conventionally, LLC resonant converter adopts frequency control (FC) or combine FC with phase shift control (PSC) to regulate the output voltage. However, for both control strategies, a variable switching frequency operation range is required, which makes the magnetic component and driver circuit design complicated. In this paper, the magnetic control (MC) or variable inductor control is adopted for the LLC resonant converter. Thanks to MC, constant switching frequency and duty cycle can be implemented for the primary switches. A comprehensive analysis of the magnetically controlled LLC resonant converter is presented, which includes the operation principle, voltage gain, and soft switching operation. Meanwhile, a design methodology for LLC resonant converter with MC is proposed, especially the design considerations for the variable inductor are discussed. By adopting the proposed design methodology, the zero voltage switching (ZVS) operation for the primary switches and the zero current switching (ZCS) operation for the secondary rectifier can be achieved. Finally, a 200 W experimental setup is built to validate the theoretical analysis.

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Section: Design Methodologymentioning

confidence: 99%

“…L LC resonant converters have drawn much attention and been widely used due to their characteristics of wide range operation, soft switching capability, and high power density [1]- [19].…”

Section: Introductionmentioning

confidence: 99%

Comprehensive Analysis and Design of LLC Resonant Converter With Magnetic Control

Wei¹,

Luo²,

Mantooth³

2019

CPSS TPEA

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“…where A is the amplitude of the primary side tank current, i.e. (see (10)) . Conduction losses for each primary and secondary metal oxide semiconductor field effect transistor (MOSFET) are given by the following relations:…”

Section: Conduction and Esr Lossesmentioning

confidence: 99%

“…State-of-the-art. Among the existing DC-DC resonant converter topologies, the half-bridge (HB) LLC resonant converter with centre-tapped secondary side would utilise the least number of active semiconductor devices, achieve wide voltage gain range and operate under soft-switching condition on both primary-and secondary-side switches, which allows it to be widely used in telecom, data center and battery charging systems [7][8][9][10][11][12][13][14][15]. The schematic of the HB LLC resonant converter with centre-tapped parallel-connected secondary-side switches is shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

High‐power‐density high‐efficiency LLC converter with an adjustable‐leakage‐inductance planar transformer for data centers

Mallik

Cooke

et al. 2019

IET Power Electronics

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LLC converters can achieve high efficiency, high-power density, wide gain range, and galvanic isolation. This study presents a high-power-density and high-efficiency LLC converter with an adjustable-leakage-inductance planar transformer for the DC-DC conversion in data center power supplies. A planar transformer with adjustable leakage inductance is modelled and developed to provide an accurate design for resonant frequency and voltage gain. A detailed power loss analysis is performed. Furthermore, a thermal model is provided to aid in heat sink design. GaN devices are used in the converter to achieve highswitching frequency and low-switching loss. A 450 kHz, 360-400 V DC input, 12 V DC output, 750 W LLC converter prototype with an adjustable-leakage-inductance planar transformer is built and tested. The power density of the system is 15.4 W/cm 3 including an auxiliary power supply. The peak efficiency of the overall system is over 95%.

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“…The design equations for the resonant frequency, transformer turns ratio, resonant inductor and resonant capacitor are shown as below [19]- [22]:…”

Section: Selection Of the Optimum Design Parametersmentioning

confidence: 99%

Application of 24V/20A LLC Resonant Converter for OLED TVs

Özçelik¹,

Obdan²

2018

Pamukkale J Eng Sci

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This study aims to come out with a double transformer resonant converter design that is serially connected in the primary part and parallel connected in the secondary part while using LLC topology. With the help of serial resonance characteristics, the power MOSFETs are conducted at zero voltage switching, therefore the switching power losses on the semiconductor devices are minimized. In the recommended converter, the primary part of two transformers are connected in series in order to transmit the load currents to output in a balanced manner. In the secondary part, the transformers are parallel connected in order to provide equal distribution of load currents. This, in return, decreased the current stresses on the secondary part of the transformers and on the output rectifying diodes. This study provides the working principle of the series resonant LLC converter topologies by designing the PSIM simulation model and laboratory prototype with 24V/20A output for OLED TV power source. Bu çalışmada, LLC topolojisi kullanılarak çift transformatör yapısı ile transformatörlerin primer tarafları seri sekonder tarafları paralel bağlı olacak şekilde rezonanslı dönüştürücü ele alınmıştır. Seri rezonans karakteristiği sayesinde güç Mosfet'leri sıfır gerilim altında iletime girmektedir, böylece yarı iletkenler üzerindeki kayıplar azalmıştır. Önerilen dönüştürücüde transformatörlerin primer sargıları birbirlerine seri bağlanmıştır, bu sayede çıkış tarafına akım dengeli bir şekilde sağlanmıştır. Sekonder tarafta transformatörlerin sargıları birbirlerine paralel bağlanmıştır böylece yük akımı eşit biçimde dağıtılmış aynı zamanda transformatörlerin sekonder sargılarının ve çıkış doğrultucu diyotlarının akım stresi azalmıştır. Bu çalışmada LLC rezonanslı dönüştürücünün çalışma prensibi ele alınmıştır ve OLED TV güç kaynakları için 24V/20A çıkışlı devrenin PSIM simülasyon modeli ve prototipi oluşturulmuştur.

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Latest Advances of LLC Converters in High Current, Fast Dynamic Response, and Wide Voltage Range Applications

Cited by 24 publications

References 36 publications

Comprehensive Analysis and Design of LLC Resonant Converter With Magnetic Control

Comprehensive Analysis and Design of LLC Resonant Converter With Magnetic Control

High‐power‐density high‐efficiency LLC converter with an adjustable‐leakage‐inductance planar transformer for data centers

Application of 24V/20A LLC Resonant Converter for OLED TVs

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