An important challenge in single-stage single-phase micro-inverters is reducing required capacitance by various active power decoupling (APD) techniques in order to use film capacitors with a longer lifetime instead of electrolytic capacitors. In this paper, a photovoltaic (PV)-side parallel APD circuit based on a bidirectional flyback converter is proposed. This topology is able to increase the average and ripple voltages for the capacitor due to having a transformer and thus can reduce the required capacitance. In the control scheme, dual control loops on the main and decoupling circuits manage the micro-inverter operation. The primary control loop is based on the instantaneous active and reactive power theory and a proportional resonant (PR) controller that is responsible for delivering the PV panel energy to the grid. The secondary control loop regulates the pulsation power on the dc-link capacitor through the PR controller. Simulation results demonstrated that the proposed APD circuit and the control method could properly damp the pulsation power in the normal and reference tracking operations. Furthermore, the good robustness of the micro-inverter was confirmed in shutdown and start-up. Finally, the experimental results with a 180-W single-phase micro-inverter prototype are presented, which validates the advantages of the proposed configuration.

中文翻译：

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微逆变器双回路控制方案的有源并联电源去耦电路

单级单相微型逆变器的一个重要挑战是通过各种有源功率去耦 (APD) 技术降低所需的电容，以便使用寿命更长的薄膜电容器代替电解电容器。在本文中，提出了一种基于双向反激式转换器的光伏（PV）侧并联 APD 电路。由于具有变压器，这种拓扑结构能够增加电容器的平均电压和纹波电压，从而可以减少所需的电容。在控制方案中，主电路和去耦电路上的双控制回路管理微型逆变器的操作。主控制回路基于瞬时有功和无功功率理论以及负责将 PV 电池板能量输送到电网的比例谐振 (PR) 控制器。次级控制回路通过 PR 控制器调节直流母线电容器上的脉动功率。仿真结果表明，所提出的 APD 电路和控制方法可以适当地抑制正常和参考跟踪操作中的脉动功率。此外，微型逆变器在停机和启动时具有良好的稳健性。最后，展示了 180 W 单相微型逆变器原型的实验结果，验证了所提出配置的优势。微逆变器在关机和启动过程中具有良好的鲁棒性。最后，展示了 180 W 单相微型逆变器原型的实验结果，验证了所提出配置的优势。微逆变器在关机和启动过程中具有良好的鲁棒性。最后，展示了 180 W 单相微型逆变器原型的实验结果，验证了所提出配置的优势。