Research On Harmonic Suppression Method Of Micro-grid

With the advantages such as being diverse and clean,micro grid has developed into an important mode of power supply.It is quite urgent to improve its stability in the practical application,especially to address the effect of higher harmonic on the electricity quality.At present,most of the load is nonlinear.Moreover,the grid has contained a large number of electrical and electronic components,which has resulted in the harmonic.Hence,the effort to suppress the harmonic is necessary to improving the electricity quality of the users.After analyzing the structure of micro grid,this paper has discussed the measures to improve the electricity quality.An in-depth analysis on the cause of the harmonic has been also made.In order to suppress the harmonic in the micro grid,this paper has proposed a new solution combining LCL micro-grid inverter and three-phase four-wire parallel APF.First of all,a model for the filter of LCL micro-grid inverter has been built.After that,a mathematical model for the split-capacitor three-phase four-wire active-power filter has been built.After analyzing a series of methods for harmonic detection,this paper has determined the methods of hysteresis control and ip-iq harmonic detection based on the stationary ABC coordinate.Lastly,a corresponding experimental model has been built with the aid of Simulink simulation platform.As shown by the experimental results,this solution can greatly reduce the distortion rate of the current in the grid.In addition,the dynamic and static responses are also verified.In the case of changing load,this solution can still achieve an excellent suppression effect.