两级式并网逆变器分时复合控制策略研究

Research on time-shared compound control strategy for two-stage grid-connected inverter

针对光伏发电系统中的两级式并网逆变器,采用了一种新型的分时复合控制策略。首先详细分析了分时复合控制策略的基本工作原理,该方法可以使得前后两级电路交替进行高频开关工作,从而有利于减小损耗;在此基础上,对分时复合控制策略下的入网电流控制环路进行小信号建模,并给出了相应的控制环路参数设计,以保证具有良好的稳态和动态性能;最后搭建了一台1 k W实验样机并进行实验验证。实验结果表明所采用分时复合控制策略的可行性和有效性。

A novel time?shared compound control strategy is presented for two?stage grid?connected inverter in photovoltaic power generation system. The working principle of the strategy is analyzed in detail. This method can make the two stages work with high?frequency switching alternately,which is helpful to decrease power losses. On the basis of the method,the current control loop under time?shared compound control strategy is conducted small signal modeling. The parameter design of relevant control loops was presented to ensure better steady state performance and dynamic performance. The 1 kW experimental proto?type was constructed and verified by experiments. The experimental results demonstrate that time?shared compound control strate?gy has feasibility and validity.