Because of the different working principles between conventional flyback and active-clamped flyback (ACF), the existing primary-side regulation (PSR) technology cannot be applied to ACF. And in order to achieve PSR of ACF, a low-cost digital sampling method based on the auxiliary winding of the transformer is proposed. In the conventional peak current mode (PCM) controlled ACF, the sampling resistor of primary current may introduce additional power loss, and high-frequency oscillations during sampling may reduce system’s stability. Therefore, a digital feedback-feedforward control (FFC) method is proposed to eliminate the sampling resistor. The stability of the proposed control method and its influence on the dynamic response are studied. In addition, since GaN device has higher power loss during reverse conduction than its Si counterpart, design considerations of reverse conduction time of power switches are also discussed in this paper. All control methods and design considerations are verified on a GaN-based 12V-3A ACF, and the proposed control strategy is implemented by FPGA.

中文翻译：

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一种采用有源钳位技术的初级侧稳压反激式数字控制新方法

由于传统反激式和有源钳位反激式 (ACF) 的工作原理不同，现有的初级侧调节 (PSR) 技术无法应用于 ACF。并且为了实现ACF的PSR，提出了一种基于变压器辅助绕组的低成本数字采样方法。在传统的峰值电流模式 (PCM) 控制的 ACF 中，初级电流的采样电阻可能会引入额外的功率损耗，并且采样期间的高频振荡可能会降低系统的稳定性。因此，提出了一种数字反馈前馈控制（FFC）方法来消除采样电阻。研究了所提出的控制方法的稳定性及其对动态响应的影响。此外，由于 GaN 器件在反向传导期间具有比其 Si 器件更高的功率损耗，本文还讨论了功率开关反向导通时间的设计考虑。所有控制方法和设计考虑都在基于 GaN 的 12V-3A ACF 上进行了验证，所提出的控制策略由 FPGA 实现。