两级式单相光伏并网系统及其仿真研究

System Simulation of Double-Stage Single-Phase Photovoltaic Inverter

以两级式并网逆变系统为控制对象,分析了整体系统的组成,研究了该光伏并网逆变系统的整体控制策略。前级最大功率跟踪(MPPT)通过调节占空比扰动控制算法进行控制;后级采用双环控制和电压前馈瞬时控制方式。应用Simulink平台搭建仿真模型进行实验验证,结果表明,所选控制方式使系统具有较好的稳定性和快速性,实现了逆变输出电流含有较小的总谐波畸变率、并与电网电压同频同相。

Taking the double-stage single-phase photovoltaic grid inverter system as a core of this paper, we analyzed the o-verall control composition and studied the whole of the PV grid inverter system control strategy .MPPT algorithm based on the ob-servation of the disturbance voltage and the back level voltage-current double loop control strategy based on feed forward are adopt-ed, whose properties are studied and simulated.Finally, the theoretical analysis and experimental are verified based on the Simu-link platform.The results show that the control method makes system have better stability and rapidity.At the same time, we real-ize the inverter output current containing lower total harmonic distortion rate （ THD） , which has the same frequency and phase as the grid.