级联式逆变器在光伏并网系统的应用研究

摘要

The circuit topology architecture of the cascading multi⁃level inverter was adopted in the photovoltaic(PV)grid⁃connected system. The control strategy of the PV grid⁃connected system based on the architecture is studied in this paper. In or⁃der to realize effective grid⁃connecting and get the same phase between current and grid voltage,the hybrid control mode with staircase control and current loop control was applied on the basis of the control strategies of single⁃stage PV grid⁃connected sys⁃tem and the cascaded inverter. Matlab/Simulink simulation analysis of the PV grid⁃connected system was conducted to verify the feasibility of the control method. The application of current loop control using PR regulator improved the efficiency of the casca⁃ded inverter.%　　采用级联式多电平逆变器的电路拓扑结构，并对基于此结构的光伏并网系统的控制策略进行研究。为实现有效并网，使得并网电流与电网电压相位一致，在结合单级光伏并网系统控制策略和级联式逆变器控制策略两者特点的基础上，采用阶梯波控制与电流环控制的混合控制方式，并对此系统进行Matlab/Simulink仿真分析，验证这种控制方法的可行性。采用PR调节器的电流环控制，提高了级联式逆变器的效率。