基于matlab的并网逆变器输出的谐波抑制研究

Research of Grid Inverter Output Harmonic Suppression Based on Matlab

逆变器是新能源并网时必不可少的部分,但它并网输出时波形中含有大量谐波,对电网电能质量造成严重的影响.本文对逆变器在SPWM控制下滤波输出的谐波抑制进行探讨,重点对工程实践中常用的几种无源滤波器的滤波情况进行了比较分析,给出了全桥逆变器拓扑结构,构建了3种滤波器的数学模型,并利用matlab软件平台进行了仿真,通过对输出电流的FFT分析发现,LCL方式滤波的总谐波畸变率最低,是一种较好的滤波方式,在并网逆变的实际中有一定的应用价值.

Inverter is a crucial part of the new energy grid, but it causes a large number of harmonics in the waveform and has a serious impact on the power quality of the grid when it works in the grid-connecting mode. This paper discusses the harmonic suppression of filter output in inverter under the control of SPWM, mainly analyzing and comparing the filtering situation of several passive filters commonly used in engineering practice, providing the topological structure of full bridge inverter, building three kinds of mathematical model of filter, and also using the matlab software platform to simulate. By analyzing FFT of the output current, it finds that the total harmonic distortion rate is the lowest through LCL filter, which is a better method of filtering and has good application value in grid-connecting inverter.