LCL型并网逆变器中重复控制方法研究

Research on Repetitive Control Method Applied to Grid-connected Inverter With LCL Filter

讨论传统控制方法在LCL型并网逆变器中的局限性,在此基础上对在LCL型并网逆变器中引入重复控制方法的可行性进行研究,分别在控制系统稳定性条件、补偿函数设计方法以及控制系统谐波抑制特性等方面做较为详细的理论分析和推导计算。总结并对比两种不同结构的重复控制与PI控制相结合的复合控制方法的优缺点。最后通过一台3.7kVA的LCL型并网逆变器样机在电网电压存在一定畸变的条件下进行实验,对所做的理论分析进行验证。

This paper discussed the limitation of the traditional control method for grid-connected inverters with an LCL filter.On this basis,the feasibility analysis on the application of the repetitive control method was carried out.Stability criterions,compensation methods,and the harmonic suppression ability were respectively analyzed in detail.Two different structures of the compound control method with both PI control and repetitive control were compared,and the advantages and disadvantages were concluded.All the theoretical analyses presented in the paper were verified by experimental results on a 3.7 kVA prototype of grid-connected inverters with an LCL filter.