Three-phase grid-connected inverter with the LCL filter is commonly controlled in synchronous frame in order to independently control active power and reactive power. And proportional-integral controller is usually adopted in synchronous frame to achieve zero steady error of inverter fundamental current. However, d–q axes cross-coupling issue may deteriorate the dynamic and steady-state performance. Moreover, the weak damping characteristic of the LCL filter will lead to resonance issue. Both issues are analyzed by the established complex-vector model of the inverter in this article. A novel multicell network control structure is proposed to address both coupling and resonance problems. To design all parameters of the multicell network controller, a multiple parameter design method is proposed. Moreover, this design method can adapt to weak grid well. Based on the proposed control structure and design method, d–q axes cross-coupling issue can be addressed thoroughly, and the damping performance is also improved obviously. Besides, the excellent steady-state and dynamic performances are realized simultaneously. Finally, the superior performances of the proposed control are verified by simulation and experimental results.

中文翻译：

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三相并网逆变器的多单元网络控制与设计

带有 LCL 滤波器的三相并网逆变器通常采用同步框架控制，以便独立控制有功功率和无功功率。同步坐标系中通常采用比例积分控制器来实现逆变器基波电流的零稳态误差。然而，d-q 轴交叉耦合问题可能会降低动态和稳态性能。此外，LCL 滤波器的弱阻尼特性会导致共振问题。本文通过建立的逆变器复矢量模型对这两个问题进行了分析。提出了一种新颖的多单元网络控制结构来解决耦合和共振问题。为了设计多小区网络控制器的所有参数，提出了一种多参数设计方法。而且，这种设计方法可以很好地适应弱电网。基于所提出的控制结构和设计方法，可以彻底解决d-q轴交叉耦合问题，阻尼性能也得到明显改善。此外，出色的稳态和动态性能同时实现。最后，通过仿真和实验结果验证了所提出的控制的优越性能。