Wide voltage gain range application for full-bridge LLC resonant converter with narrow switching frequency range

This paper presents a inductor–inductor–capacitor (LLC) resonant converter with variable winding turns to achieve wide voltage operation (100–400 V) and realize soft switching operation over the entire load range. Resonant converters have been developed for consumer power units in computers, power servers, medical equipment, and adaptors due to the advantages of less switching loss and better circuit efficiency. The main disadvantages of the LLC resonant converter are narrow voltage range operation owing to wide switching frequency variation and limited voltage gain. For computer power supplies with hold-up time function, electric vehicle battery chargers, and for power conversion in solar panels, wide input voltage or wide output voltage operation capability is normally demanded for powered electronics. To meet these requirements, the variable winding turns are used in the presented circuit to achieve high- or low-voltage gain when Vin is at low- or high-voltage, respectively. Therefore, the wide voltage operation capability can be implemented in the presented resonant circuit. The variable winding turns are controlled by an alternating current (AC) power switch with two back-to-back metal-oxide-semiconductor field-effect transistors (MOSFETs). A 500-W prototype is implemented and test results are presented to confirm the converter performance.

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Accurate Prediction of Voltage Gain of the LLC Resonant Converter for EV battery Charge Applications

Academic Perspective Procedia ◽

10.33793/acperpro.01.01.105 ◽

2018 ◽

Vol 1 (1) ◽

pp. 544-557 ◽

Cited By ~ 1

Author(s):

Sevilay Cetin

Keyword(s):

Output Voltage ◽

Harmonic Approximation ◽

Voltage Regulation ◽

Accurate Prediction ◽

Switching Frequency ◽

Voltage Gain ◽

Resonant Converter ◽

Battery Charge ◽

Wide Range ◽

Llc Resonant Converter

This work presents detailed analysis of LLC resonant converter to accurately predcit the voltage gain of the converter. Nowadays, Lithium-ion battery cells are mostly preferred for on-board electrical vehicle (EV) battery chargers due to their high power density. This results in wide range output voltage regulation for battery charger. The output voltage regulation of LLC resonant converter is provided by the changing of switching frequency. However, conventional first harmonic approximation (FHA) method applying for resonant power converters produces error below resonance frequency. Therefore, the objective of this paper is accurate prediction of the voltage gain characteristic for LLC resonant converter using in EV battery charge applications. The detailed theoretical anlysis of the LLC resonant converter is presented and the presented analysis is compared with a simulation study with 2.7 kW output power and 250 V-450 V output voltage range.

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FHA-based voltage gain function with harmonic compensation for LLC resonant converter

2010 Twenty-Fifth Annual IEEE Applied Power Electronics Conference and Exposition (APEC) ◽

10.1109/apec.2010.5433473 ◽

2010 ◽

Cited By ~ 21

Author(s):

Hong Huang

Keyword(s):

Voltage Gain ◽

Resonant Converter ◽

Gain Function ◽

Harmonic Compensation ◽

Llc Resonant Converter

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An Accurate Voltage Gain Model Considering Diode Effect for LLC Resonant Converter in Wide Gain Range Applications

2020 IEEE Energy Conversion Congress and Exposition (ECCE) ◽

10.1109/ecce44975.2020.9236329 ◽

2020 ◽

Author(s):

Hao Wen ◽

Dong Jiao ◽

Jih-Sheng Lai ◽

Johan Strydom ◽

Lanhua Zhang

Keyword(s):

Voltage Gain ◽

Resonant Converter ◽

Llc Resonant Converter

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Univesal Design of LLC Resonant Converter with Fixed Switching Frequency

10.1109/iciba50161.2020.9277356 ◽

2020 ◽

Author(s):

Jiangtao Xu ◽

Yun Wei ◽

Xin Cheng ◽

Hua Yang ◽

Hongxiang Xue ◽

...

Keyword(s):

Switching Frequency ◽

Resonant Converter ◽

Llc Resonant Converter

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An 8kW LLC resonant converter in plasma power supply based on SiC power devices for efficiency improvement

Circuit World ◽

10.1108/cw-07-2018-0058 ◽

2019 ◽

Vol 45 (4) ◽

pp. 181-188

Author(s):

Zhenmin Wang ◽

Wenyan Fan ◽

Fangxiang Xie ◽

Chunxian Ye

Keyword(s):

Silicon Carbide ◽

Power Supply ◽

High Frequency ◽

Experimental Results ◽

Switching Frequency ◽

Resonant Converter ◽

Plasma Power ◽

Power Devices ◽

Content Type ◽

Llc Resonant Converter

Purpose This paper aims to present an 8 kW LLC resonant converter designed for plasma power supply with higher efficiency and lighter structure. It presents how to solve the problems of large volume and weight, low performance and low efficiency of traditional plasma power supply. Design/methodology/approach At present, conventional silicon (Si) power devices’ switching performance is close to the theoretical limit determined by its material properties; the next-generation silicon carbide (SiC) power devices with outstanding advantages can be used to optimal design. This 8 kW LLC resonant converter prototype with silicon carbide (SiC) power devices with a modulated switching frequency ranges from 100 to 400 kHz. Findings The experimental results show that the topology, switching loss, rectifier loss, transformer loss and drive circuit of the full-bridge LLC silicon carbide (SiC) plasma power supply can be optimized. Research limitations/implications Due to the selected research object (plasma power supply), this study may have limited universality. The authors encourage the study of high frequency resonant converters for other applications such as argon arc welding. Practical implications This study provides a practical application for users to improve the quality of plasma welding. Originality/value The experimental results show that the full-bridge LLC silicon carbide (SiC) plasma power supply is preferred in operation under conditions of high frequency and high voltage. And its efficiency can reach 98%, making it lighter, more compact and more efficient than previous designs.

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A Novel Dual Integrated LLC Resonant Converter Using Various Switching Patterns for a Wide Output Voltage Range Battery Charger

Electronics ◽

10.3390/electronics8070759 ◽

2019 ◽

Vol 8 (7) ◽

pp. 759

Author(s):

Bong-Yeon Choi ◽

Soon-Ryung Lee ◽

Jin-Wook Kang ◽

Won-Sang Jeong ◽

Chung-Yuen Won

Keyword(s):

Output Voltage ◽

Voltage Gain ◽

Resonant Converter ◽

Operating Characteristics ◽

Battery Charger ◽

Voltage Range ◽

Switching Pattern ◽

Operating Frequency Range ◽

Switching Patterns ◽

Llc Resonant Converter

This paper proposes a novel dual integrated LLC resonant converter (DI-LRC) with a wide output voltage range using various switching patterns. The primary side of the proposed DI-LLC converter consists of two resonant tanks and six switches, while the secondary side consists of a six-pulse diode rectifier. Depending on the switching pattern of the primary switch, the DI-LRC converter is performed by single full-bridge operation with a voltage gain of 1, series-connected full-bridge operation with a voltage gain of 0.5, series-connected half bridge operation with a voltage gain of 0.25, and parallel-connected full-bridge operation with a voltage gain of 2. Accordingly, the proposed DI-LRC converter has four voltage gain curves with different variations and achieves a wider output voltage range than the conventional single voltage gain curve in a given operating frequency range. In this paper, the equivalent circuits derived for each switching pattern are proposed to analyze the operating characteristics of the proposed converter according to each switching pattern, and each Q factor and voltage gain are calculated based on the analyzed equivalent circuit. The performance of the proposed converter and switching pattern is verified using the simulation and experimental results of the prototype battery charger, which is designed to be 4-kW class.

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