Research On Active Power Filter Applied For Microgrid

In the situation of diversification of mode in energy using and high demand forelectricity standardization, improving the reliability of power supplying to ensure the qualityof it from micro-grid is necessary. While the power harmonics is one of the main reasoninfluencing the power quality of micro-grid(MG) system. In this article, there is a research onthe APF which is effective in suppressing harmonic of MG.This research has its practicalsignificance and application value for the power quality assurance of MG.Because of the large quantity and dispersion of harmonic source, this article analyzes theharmonic phenomenon existed in MG from power generation to use and the harmonicinteraction factors between different harmonic source. Amplification appears in thecommunication process of the harmonic. So it is lack of specificity to achieve overallharmonic inhibition in MG when comparing with single harmonic source suppression.It will increase the harmonic content of other nodes when the traditional active filter isused in MG. Taking this into account, according to the principle of harmonic amplificationadjacent segments, the article makes a research on APF based on virtual impedance detectionmethod. The APF play a role as a virtual impedance by detecting voltage and output currentproportional relationship, which can inhibit the spread of harmonics. It has little effect onother nodes, while reducing the the harmonic content of the access point efficiently, and isgood for controlling harmonic content of entire system. To solve harmonic injection issue oftriangular wave comparison tracking control method, design LCL output filter, avoiding theimpact on the compensation effect of switching harmonics.Make a simulation of the APF studied in this article using MATLAB/simulinksimulation software. The result supports the effectiveness of the APF applied for MG,especially in the situation of multi-harmonic sources.