基于LC滤波的光伏逆变器电感电流反馈控制策略研究

针对光伏并网逆变器的特点，基于电感电流反馈控制的光伏并网逆变器，提出了参考电流相位超前的电流内环控制策略。通过分析单相并网逆变器结构，推导了LC滤波器上电压电流矢量关系。加入电网电压瞬时值前馈解耦控制，研究了比例调节和准比例谐振调节两种策略下参考电流与输出电流的关联。基于一台3 kW逆变器为实验平台的理论分析和实验结果表明，采用该策略的逆变器并网电流时刻跟踪电网电压频率和相位，功率因数为1，并网电流谐波失真度低于3%。

Study on Inductor Current Feedback Control Strategy ofPhotovoltaic Grid-connected Inverter Based on LC Filter

According to the features of grid-connected photovoltaic (PV) inverter, an advancing reference current loop control strategy based on the inverter with inductor current feedback was proposed. By analyzing the structure of single-phase grid connected inverter, the vector relationship between voltage and current on LC filter was presented. Proportional regulation and proportional-resonant regulation with the gird voltage feed-forward decoupling controlling was adopted to study the relevance between reference current and output current. Theoretical analysis and experimental results based on a 3 kW inverter experimental platform show that the output current of the inverter can track the frequency and the phase of the grid voltage well, the power factor is unity, and the total harmonic distortion of output current is below 3%.