In single-phase ac/dc applications where reliability and/or power-density are critical, active power decoupling (APD) circuits can be employed to reduce the required capacitance on the dc-link. Various APD circuits have been proposed so far, all with their advantages and disadvantages. However, many confusions still exist in the literature on this topic which is mainly attributed to a lack of unified and comprehensive assessment criteria. In this paper, first the decisive criteria for a modern APD circuit are established, and the buck APD is identified as the current state-of-the-art, based on them. Then the buck-plus-unfolder topology with triangular current mode (TCM) modulation is proposed as an improvement, and a simple, yet solid foundation is introduced to choose the superior decoupling solution at different specifications. The operation equations for the APD with TCM modulation are derived next, and the operation of the proposed solution is demonstrated using a hardware prototype.

中文翻译：

---

Buck-Plus-Unfolder作为适用于400 Vdc / kW级应用的高级有源功率去耦解决方案

在可靠性和/或功率密度至关重要的单相交流/直流应用中，可以采用有功功率去耦（APD）电路来减少直流链路上所需的电容。迄今为止，已经提出了各种APD电路，它们都有其优点和缺点。但是，关于该主题的文献仍然存在许多困惑，这主要是由于缺乏统一和全面的评估标准。在本文中，首先建立了现代APD电路的决定性标准，并基于它们确定了Buck APD是当前的最新技术。然后，提出了一种采用三角电流模式（TCM）调制的降压加展开式拓扑，作为一种改进，并引入了一个简单而坚实的基础来选择不同规格的优良去耦解决方案。