Critical conduction mode (CrCM) active clamp flyback (ACF) converter is regarded as a good candidate to be applied in high-frequency small power supplies. This article focuses on the modeling, analysis, and controller design of CrCM-ACF converter. The small signal model of the converter is derived based on a zero-input resonant equivalent circuit and extended describing function (EDF) method for the first time, then the obtained full-order model is simplified to a low-order model. This procedure establishes an insightful understanding about the effects of the converter parameters and working conditions. Based on the simplified model, a control loop compensator is designed in a single-loop voltage-feedback control scheme for high dynamic performance. An experimental prototype of digital controlled CrCM-ACF converter is built, the accuracy of the derived model is verified by comparing with experimental and simulation results. The performance of the compensator is experimentally evaluated by applying abrupt load current and reference voltage changes in the operating conditions of the converter. From the experimental results, it is demonstrated that the derived analytical model and designed compensator are effective in regulating the output voltage in CrCM-ACF converter.

中文翻译：

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临界传导模式有源钳位反激转换器的小信号建模和控制环路设计

临界传导模式（CrCM）有源钳位反激（ACF）转换器被认为是适用于高频小电源的很好的选择。本文重点介绍CrCM-ACF转换器的建模，分析和控制器设计。基于零输入谐振等效电路并首次采用扩展描述函数（EDF）方法导出转换器的小信号模型，然后将获得的全阶模型简化为低阶模型。此过程可对变频器参数和工作条件的影响建立深刻的了解。基于简化模型，在单回路电压反馈控制方案中设计了控制回路补偿器，以实现高动态性能。建立了数控CrCM-ACF转换器的实验原型，通过与实验和仿真结果进行比较，验证了导出模型的准确性。通过在转换器的工作条件下施加突然的负载电流和参考电压变化，可以通过实验评估补偿器的性能。实验结果表明，所推导的解析模型和设计的补偿器可以有效地调节CrCM-ACF转换器的输出电压。