吴海军,鲍鹏飞,王范华,郭浩,苗自亮,范陕渭,马伏军
WU Haijun,BAO Pengfei,WANG Fanhua,GUO Hao,MIAO Ziliang,FAN Shanwei,MA Fujun

• 1:内蒙古察哈尔新能源有限公司
• 2:新源智储能源发展(北京)有限公司
• 3:湖南大学电气与信息工程学院

摘要(Abstract)：

在大功率直流变换领域，ISOP（输入串联输出并联）结构的CLLLC谐振变换器凭借器件耐压低、功率密度高的优势而广泛应用，但受参数离散性及恒功率负载负阻抗等影响，存在输入均压失衡问题。为此，提出一种基于误差动态感知的自适应虚拟阻抗均压策略。采用EDF（扩展描述函数）法建立CLLLC变换器11阶小信号模型，明确状态方程系数矩阵的物理意义，推导输入阻抗简化表达式以揭示均压失衡机理。设计随电压误差非线性变化的虚拟电阻R_v与虚拟电感L_v，在暂态大偏差时增大R_v并提高L_v的超前补偿强度以加速收敛，在稳态小偏差时使R_v回落以降低等效压降及纹波耦合，同时令L_v回落以抑制微分噪声注入与频率微调抖动。实验结果表明，该策略无需额外硬件即可重塑子模块等效输入阻抗并显著改善均压性能；相较于传统方法，该策略稳态均压偏差更小，且对参数失配及工况扰动的鲁棒性更强，为大功率系统可靠运行提供了理论依据。
In high-power DC conversion applications, CLLLC resonant converters with an ISOP(input-series output-parallel) configuration are widely used due to their low device voltage stress and high power density. However, affected by parameter dispersion and the negative impedance characteristic of constant power loads, input voltage imbalance remains a critical issue. To address this, an adaptive virtual impedance-based voltage balancing strategy with dynamic error perception is proposed. An 11 th-order small-signal model of the CLLLC converter is established using the extended describing function(EDF) method, the physical significance of the state-space coefficient matrix is clarified, and a simplified expression of input impedance is derived to reveal the mechanism of voltage imbalance. A virtual resistance Rv and virtual inductance Lv are designed to vary nonlinearly with voltage error. Under large transient deviations, Rv is increased and the leading compensation effect of Lv is enhanced to accelerate convergence; under small steady-state deviations, Rv is reduced to decrease equivalent voltage drop and ripple coupling, while Lv is decreased to suppress differential noise injection and frequency-tuning oscillations. Experimental results demonstrate that the proposed strategy reshapes the equivalent input impedance of submodules without additional hardware and significantly improves voltage balancing performance. Compared with conventional methods, it achieves smaller steady-state voltage deviation and stronger robustness against parameter mismatch and operating condition disturbances, providing a theoretical basis for reliable operation of high-power systems.

关键词(KeyWords)： 输入串联输出并联;CLLLC谐振变换器;虚拟阻抗;输入均压;扩展描述函数法;自适应控制
ISOP;CLLLC resonant converter;virtual impedance;input voltage balancing;EDF method;adaptive control

Abstract:

Keywords:

基金项目(Foundation): 湖南省重点研发计划（2024JK2105）

作者(Author): 吴海军,鲍鹏飞,王范华,郭浩,苗自亮,范陕渭,马伏军
WU Haijun,BAO Pengfei,WANG Fanhua,GUO Hao,MIAO Ziliang,FAN Shanwei,MA Fujun

DOI: 10.19585/j.zjdl.202608007

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