基于虚拟相电路的单相并网逆变器矢量控制

Vector Control for Single-phase Grid-connected Inverter Based on Virtual-phase Circuit

通过构造虚拟电压、虚拟电流,在按电网电压定向的同步旋转d,q坐标系下对单相并网逆变器的输出电流进行控制,即矢量控制。在d,q坐标系下,交流量变换为直流量,可采用PI控制器对并网电流实现稳态无静差的控制。当采用构造虚拟电压的方法构造虚拟电流时,会使单相并网变换器的动态响应变差,即产生振荡和动态过程变慢。提出了一种虚拟相电路(VPC)的方法,相比传统方法,用该方法构造虚拟电流可有效改善单相并网逆变器的动态响应性能。最后,实验结果验证了该方法的正确性和有效性。

By constructing virtual voltage and virtual current,regulates the current of single-phase grid-connected inverter in direct-quadrature（d,q） synchronous reference frames which directed by the grid voltage,which is vector control.In a d,q reference frame,AC quantities appear as DC ones,allowing the PI controller to be designed to achieve zero steady-state error.When the method of constructing virtual voltage is adopted to constructing virtual current,the dy-namic response of the inverter is deteriorated,which becomes slower and oscillatory.The virtual-phase circuit（VPC） is generated.The proposed approach effectively improves the poor dynamics of the conventional approaches.Finally,the experimental results illustrate the validity and effectiveness of the proposed approach.