中文摘要：

针对单相并网变流系统采用传统的比例积分（PI）控制器在跟踪并网电流指令时存在稳态误差，以及传统的比例谐振（PR）控制器在离散化过程中存在谐振点偏移的缺陷，提出一种新的离散比例谐振（DPR）控制器。该控制器包含比例项，前馈项和谐振项。谐振项采用一组离散二阶状态方程实现，替代传统PR控制器离散化后的二阶差分方程，能使控制器具有无静差的稳态特性。与传统PR控制器相比，由于谐振项直接采用离散状态方程实现，DPR控制器不会因为离散过程导致谐振点偏移而影响控制器性能。最后通过实验验证了该方法的有效性。

英文摘要：

Since the single-phase grid-connected Converter system with traditional PI controller has steady-state error in tracking the grid-connected current instruction,and traditional proportion resonant （PR） controller has defects of the resonant point shift in the discretization process,a new discrete proportion resonant（DPR）controller is proposed in this paper. The con-troller contains proportional,feedforward and resonant terms. A set of discrete second-order state equation is adopted for imple-mentation of the resonant term to replace the second-order differential equation of traditional PR controller after discretization. It can make the controller has non-static error characteristics. Compared with the traditional PR controller,DPR controller will not result in resonance point shift by discrete process and then affect controller performance because the resonant term is directly realized by the discrete state equation. The effectiveness of the method was verified by experiments.