并网逆变器输出电压直流分量的研究

与独立工作的逆变器相比,并网逆变器不仅要保证低的输出电压谐波畸变率和高效率,而且要求输出电压与电网电压大小、相位一致,更重要的是必须保证有低的进网电流谐波畸变率,以免对电网造成污染.双Buck逆变器类似于半桥逆变器,输入侧分压电容的电压偏差受很多因素的影响.分析了输出电压中的直流分量与分压电容电压偏差的关系以及对进网电流谐波畸变率的影响,并进行了实验验证.

Research on DC Bias Components in Output Voltage of Grid-connected Inverter

Compared with independent inverters,grid-connected inverter should ensure low Total Harmonic Distortion(THD) of the output voltage and high efficiency,and keep accordance with the utility.The most important is that the grid-connected inverter should also ensure low grid current THD to avoid the grid pollution.Double Buck inverter is similar to the half-bridge inverter.The voltage displacement of the two capacitors at the input terminal was affected by several causes.This paper analyzes the relationship between the DC components of the output voltage and the voltage variation of the ca-pacitors at the input terminal,as well as the grid current THD influenced by the dc components of the output voltage.In the end,it is verified by experiments.