A Novel Digital Control Method of a Single-Phase Grid-Connected Inverter Based on a Virtual Closed-Loop Circuit and Complex Vector Representation

Energies

Gangyi Hu¹  Zhibi Lyu²  Yangxiao Xiang²  Hong Yi³  Kun Xie³ 

[1] China Ship Development and Design Center, Wuhan 430064, China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, China;State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;

关键词: single-phase inverter;    virtual closed-loop circuit;    current decoupling control;    complex vector;    discrete domain;   

DOI  :  10.3390/en10122068

来源: DOAJ

【 摘 要 】

With the rapid development of renewable energy generation, single-phase grid-connected inverters have been widely applied in modern power systems. Since the power output of the renewable sources is continuously changing, independent active/reactive power control and a rapid current tracking performance is supposed to be achieved in a single-phase grid-connected inverter. However, the poor orthogonal-axis-constructing strategy and the ineffective decoupling in some widely-used controllers have severely weakened the dynamic performance of the single-phase inverter. To deal with the challenges above, this study proposes a comprehensive control strategy for current control in a single-phase grid-connected inverter. In the proposed control strategy, a virtual closed-loop is constructed to improve the dynamic performance and realize independent power control under a synchronous frame. Then, complex vector theory is used to model the virtual closed-loop based single-phase inverter, and a novel digital controller is designed based on zero-pole cancellation and minimum beat control to completely decouple the active/reactive components and achieve a supreme current tracking performance. Experimental results are shown to validate the feasibility of the proposed current controller.

【 授权许可】

Unknown