Research On Control Method For Inverter Of Photovoltaic Generation System

With the conventional energy sources are depleting and the energy crisis has become increasingly prominent,the prospects of solar photovoltaic power generation are becoming more and more important.As an important component of the PV system,the performance of inverter is directly related to the operation of the photovoltaic power generation system.In this article,the single-phase photovoltaic inverter is the research object and a method of controlling it is deeply analyzed.Aiming at the characteristics of photovoltaic system,the compositions of the photovoltaic power generation system are analyzed.To meet the requirements of the energy conversion system,this article selects multi-stage,full-bridge circuit structure,and controls the inverter by selecting the unipolar pulse width modulation.In this article,the types of photovoltaic grid system filter and its mathematical model are analyzed detailedly.A LLCL filter is furnished to suppress high frequency switch and the parameters of the filter are designed.Then a hybrid damping control method of LLCL filter is proposed.On this basis,this paper designed a new composite control method to control the PV grid-connected inverter.To use the dynamic performance and stability of the methods fully,this control method combines the quasi-resonant control method and the repetitive control method together and the parameters of the method are also designed.Finally,by simulation experiments the verification and analysis of the proposed control method are proved,the reasonableness of the proposed PV grid inverter control method is verified.