LLC resonant converter has been widely used in many applications due to its characteristics of high efficiency and high frequency characteristics. Analysis method plays great role in converter design and operation performance. For LLC resonant converter, the most frequently used analysis methods are frequency-domain analysis (FDA) and time-domain analysis (TDA). FDA assumes that only fundamental harmonics can deliver energy in the system, while TDA is obtained by solving circuit state equations. In this study, comprehensive and complete comparisons between FDA and TDA in terms of analysis methodology, parameter design, analysis accuracy, conduction loss, other power losses, and system efficiency are implemented. The analysis and comparison results show that under the same system specifications, by adopting TDA, a larger magnetising inductance value can be used when compared with FDA, which will reduce the resonant tank circulating current and increase the system efficiency. The comprehensive analysis can provide guidance for engineers when analysing and designing LLC resonant converter. Finally, a 200 W experimental prototype was built and tested to verify the theoretical analysis.

中文翻译：

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LLC谐振转换器的频域分析与时域分析的全面比较

LLC谐振转换器因其高效率和高频特性而被广泛用于许多应用中。分析方法在变流器设计和运行性能中起着重要作用。对于LLC谐振转换器，最常用的分析方法是频域分析（FDA）和时域分析（TDA）。FDA假设只有基本谐波才能在系统中传递能量，而TDA是通过求解电路状态方程获得的。在这项研究中，在分析方法论，参数设计，分析准确性，传导损耗，其他功率损耗和系统效率方面，对FDA和TDA进行了全面而全面的比较。分析比较结果表明，在相同的系统规格下，采用TDA，与FDA相比，可以使用更大的励磁电感值，这将减少谐振回路的循环电流并提高系统效率。全面的分析可以为工程师在分析和设计LLC谐振转换器时提供指导。最后，构建并测试了200 W的实验原型以验证理论分析。