Research On Application Of Series Active Power Filter In Microgrid

With the rapid development of the global industrial technology and the growth of theelectricity demand, more and more problems begin to be exposed of the main power grid.As the new field of the main power grid, the studies of microgrid aroused general interest.The inverter and other power electronic devices of the microgird, will bring lots ofharmonic problem. Furthermore, the power quality of microgrid have been worsened bythe randomness of the photovoltaic power and wind power. In this paper, the problem ofthe power harmonic suppression for microgrid is investigated, in order to ensure thestability, security and the economic operation of the microgrid.According to the system impedance characteristics and the basic structure of themicrogrid, the PV/Qf droop control model is established. The power harmonics’mechanism of the microgrid is analyzed, on the basis of the microgrid control model.According to the voltage harmonics problem by the resistive line impedance and localnonlinear RC loads of low-voltage microgrid, A detailed description of the series activepower filter is introduced, the method of detecting base on instantaneous reactive powerip-iqtheory is studied and improved in this paper. By the established of the SAPF(SeriesActive Power Filter) equivalent model, the traditional detection method of load voltageharmonics is proven to be improper, and the new complex detection method of loadvoltage harmonics and source current harmonics is selected. The improved resonantcontroller is chosen in harmonic tracking. The microgrid simulation mode is set up byusing MATLAB/Simulink software, and the non-linear load is added. The validity andrationality of the SAPF’s control method is proved, by the improved of the PCC’s powerquality.The microgrid harmonics experimental platform is established in the laboratory,which include three inverters and one of those inverters is SAPF. On the basis of theexperimental paltform, the droop control of the microgrid and the harmonic compensationof the SAPF is performed. The experimental results show that the validity of the harmonicimprovement in the microgrid is proved by the suitable control method of the SAPF.