The increasing penetration of distributed generators in low-voltage distribution grids may lead to distribution transformers, also a smart transformer, experiencing the reverse power flow, which is less as compared to the forward power flow in the current electric grid. This article proposes an asymmetrical bidirectional dc–dc (AB-DC/DC) converter, which has two partial-scale rectifiers of an active bridge and a diode bridge connected in parallel at the secondary side, with less cost of power semiconductors and the capability of bidirectional operation to satisfy the realistic condition. The proposed AB-DC/DC converter works as a single active bridge under forward power flow condition, while it works as a dual active bridge under reverse power flow condition. The solutions to share the active power under forward operation and suppress the circulating power under reverse operation are proposed, respectively. The simulation and experimental results both clearly validate the effectiveness and feasibility of the proposed AB-DC/DC converter.

中文翻译：

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智能变压器中具有有限反向额定功率的非对称双向 DC/DC 转换器

分布式发电机在低压配电网中的日益普及可能导致配电变压器，也是一种智能变压器，经历逆潮流，与当前电网中的正向潮流相比，逆潮流要小。本文提出了一种非对称双向 dc-dc (AB-DC/DC) 转换器，它在次级侧并联了一个有源电桥和一个二极管电桥的两个部分规模整流器，功率半导体成本低，容量的双向操作以满足现实条件。所提出的 AB-DC/DC 转换器在正向功率流条件下作为单有源电桥工作，而在反向功率流条件下作为双有源电桥工作。分别提出了正向运行时共享有功功率和反向运行时抑制循环功率的解决方案。仿真和实验结果都清楚地验证了所提出的 AB-DC/DC 转换器的有效性和可行性。