基于平面磁元件的LLC变换器相关参数的整体优化设计方法

doi:10.19595/j.cnki.1000-6753.tces.230778

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Abstract Traditional step-by-step optimization design methods struggle with the large number, strong continuity, and mutual coupling of planar magnetic elements, which is challenging to achieve the highest overall efficiency. Therefore, this paper proposes a parameter global optimization design method for the LLC converter based on planar magnetic elements to enhance efficiency and power density, including the switching frequency, resonant parameters (parallel-to-series resonance inductance ratio, resonance capacitance), the size of planar magnetic elements (middle leg radius, winding linewidth, transformer and inductance middle leg length, middle leg height), and the output power at peak efficiency.
The optimization objective is to maximize the peak efficiency of the converter, expressed as the optimization parameters. The optimization constraints are the working stress and volume of the converter related to the optimization parameters to meet practical engineering requirements. The optimization design is expressed as a single objective, multi-parameter, nonlinear problem. Genetic algorithm (GA), particle swarm optimization (PSO), simulated annealing algorithm (SA), traversal optimization, and other methods can be used to solve this problem. The theoretical global optimal design parameters for maximizing the peak efficiency can be obtained in a single step.
Compared with the step-by-step design method, the parameter global optimization design method can improve the theoretical peak efficiency for a certain LLC converter by about 0.1%, with a reduction of more than 20% in the volume of the planar magnetic element. This improvement is achieved by reducing the switching loss of switching devices and the core loss of the magnetic element by an appropriate decrease in the switching frequency and allocating more of the total area of the magnetic element to the magnetic core rather than the winding. The efficiency at each working condition below half load is improved, validating the effectiveness of the parameter global optimization design method.
A 3 kW high-efficiency and high-power density LLC converter is designed. Considering that the optimization parameters are variables with practical physical significance and processing technology constraints, the traversal optimization method can ensure that the optimization results are the actual values achieved in production by setting the appropriate step size. The power density of the converter is 510 W/in³, the peak efficiency is 99.0%, and the full load efficiency is 98.3%. The result is close to the theoretical results of the parameter global optimization design method, which proves the correctness and effectiveness of the design method.
The idea is also applicable to other topologies using planar magnetic elements. The application to other topologies involves similar thinking, with specific optimization parameters and their relationships tailored to each case.

Key words： LLC converter planar magnetic parameters design high efficiency

Received: 29 May 2023

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	Zhou Zihang
	Gao Yihan
	Liu Yijing
	Zhang Xin
	Ma Hao

Cite this article:

Zhou Zihang,Gao Yihan,Liu Yijing等. Parameters Global Optimization Design Method for LLC Converter with Planar Magnetic[J]. Transactions of China Electrotechnical Society, 2024, 39(15): 4820-4829.

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https://dgjsxb.ces-transaction.com/EN/10.19595/j.cnki.1000-6753.tces.230778 OR https://dgjsxb.ces-transaction.com/EN/Y2024/V39/I15/4820

[1] 郭强, 李山, 谢诗云, 等. 多相交错并联DC-DC变换器单电流传感器控制策略[J]. 电工技术学报, 2022, 37(4): 964-975.
Guo Qiang, Li Shan, Xie Shiyun, et al.Single-sensor sampling current control strategy of multiphase interleaved DC-DC converters[J]. Transactions of China Electrotechnical Society, 2022, 37(4): 964-975.
[2] 李福, 邓红雷, 张国驹, 等. 一种中间电容谐振型级联双向DC-DC变换器[J]. 电工技术学报, 2022, 37(20): 5253-5266.
Li Fu, Deng Honglei, Zhang Guoju, et al.A cascaded bidirectional DC-DC converter with intermediate capacitor resonance[J]. Transactions of China Elec- trotechnical Society, 2022, 37(20): 5253-5266.
[3] 丁超, 李勇, 姜利, 等. 电动汽车直流充电系统LLC谐振变换器软开关电压边界分析[J]. 电工技术学报, 2022, 37(1): 3-11.
Ding Chao, Li Yong, Jiang Li, et al.Analysis of soft switching voltage boundary of LLC resonant con- verter for EV DC charging system[J]. Transactions of China Electrotechnical Society, 2022, 37(1): 3-11.
[4] 李广地, 阮杰, 王昆, 等. 一种混合调制型三路输出DC-DC变换器[J]. 电工技术学报, 2019, 34(22): 4719-4727.
Li Guangdi, Ruan Jie, Wang Kun, et al.A hybrid modulated triple-output DC-DC converter[J]. Transa- ctions of China Electrotechnical Society, 2019, 34(22): 4719-4727.
[5] 林辉品. 宽范围LLC谐振变换器的研究[D]. 杭州: 浙江大学, 2019.
[6] 王媛媛. 基于GaN器件的高频DC/DC变换器的研究[D]. 哈尔滨: 哈尔滨工业大学, 2018.
[7] 韦玉麒. 磁控制LLC谐振变换器的研究[D]. 重庆: 重庆大学, 2019.
[8] Nabih A, Li Qiang.Low-profile and high-efficiency 3 kW 400 V-48 V LLC converter with a matrix of four transformers and inductors for 48V power architecture for data centers[C]//2021 IEEE Energy Conversion Congress and Exposition (ECCE), Vancouver, BC, Canada, 2021: 1813-1819.
[9] Prakash P R, Nabih A, Li Qiang.Termination design optimization of high-current PCB-winding matrix transformers[J]. IEEE Transactions on Power Elec- tronics, 2023, 38(4): 4957-4971.
[10] Liu Yue, Wu Hongfei, Tai Yu, et al.Optimal design of GaN and PCB-winding based transformer-inductor- integrated magnetics for CLL resonant converter[C]// 2020 IEEE Energy Conversion Congress and Expo- sition (ECCE), Detroit, MI, USA, 2020: 5430-5435.
[11] Nabih A, Li Qiang, Lee F C.Magnetic integration of four-transformer matrix with high controllable leakage inductance using a five-leg magnetic[C]// 2022 IEEE Applied Power Electronics Conference and Exposition (APEC), Houston, TX, USA, 2022: 693-700.
[12] Huang Qingyun, Ma Qingxuan, Huang A Q, et al.400V-to-48V GaN modular LLC resonant converter with planar transformers[C]//2021 IEEE Energy Conversion Congress and Exposition (ECCE), Vancouver, BC, Canada, 2021: 2129-2135.
[13] Nabih A, Gadelrab R, Prakash P R, et al.High power density 1 MHz 3 kW 400 V-48 V LLC converter for datacenters with improved core loss and termination loss[C]//2021 IEEE Applied Power Electronics Conference and Exposition (APEC), Phoenix, AZ, USA, 2021: 304-309.
[14] Gadelrab R, Nabih A, Lee F C, et al.LLC resonant converter with 99% efficiency for data center server[C]//2021 IEEE Applied Power Electronics Conference and Exposition (APEC), Phoenix, AZ, USA, 2021: 310-319.
[15] 肖龙, 伍梁, 李新, 等. 高频LLC变换器平面磁集成矩阵变压器的优化设计[J]. 电工技术学报, 2020, 35(4): 758-766.
Xiao Long, Wu Liang, Li Xin, et al.Optimal design of planar magnetic integrated matrix transformer for high frequency LLC converter[J]. Transactions of China Electrotechnical Society, 2020, 35(4): 758-766.
[16] Ranjram M K, Perreault D J.A 380-12 V, 1-kW, 1-MHz converter using a miniaturized split-phase, fractional-turn planar transformer[J]. IEEE Transa- ctions on Power Electronics, 2022, 37(2): 1666-1681.
[17] Nabih A, Li Qiang.Design of 98.8% efficient 400- to-48 V $LLC$ converter with optimized matrix transformer and matrix inductor[J]. IEEE Transa- ctions on Power Electronics, 2023, 38(6): 7207-7225.
[18] Fei Chao, Gadelrab R, Li Qiang, et al.High-frequency three-phase interleaved LLC resonant converter with GaN devices and integrated planar magnetics[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2019, 7(2): 653-663.