Study On Grid-connected Inverter For Photovoltaic Power Generation System

Nowadays,the human society is in a state of continuous and high-speed development.With the number of population is increasing,energy shortage and environmental pollution have become an important problem facing the society.With human beings continue to pursue higher living standards throughout the world,the demand for clean energy is still increasing.Therefore,the development of new energy has become a problem to be solved urgently.As a device to connect the grid to a photovoltaic array or even a distributed generation system,grid-connected inverter plays an important role.This paper designs a single-phase inverter for grid-connected photovoltaic power generation.After comparing and analyzing the main features of the L and the LCL filters of the output end of inverter,the LCL filter is adopted as the filter of this system.Around the LCL filter parameter design problems,this paper design the parameters of LCL filter from the total inductance?inverter side inductance?grid side inductance and capacitance value analysis of the system in the terms of the Bode diagram analysis.And use active damping to solve the problem of the inherent resonant of LCL filter.Designs the current controller and us the method of capacitor current feedback to make the system stable.Setting up the system simulation model by MATLAB/Simulink,the simulation results show that the parameters of LCL filter and power inverter design in the flow controller meet the design requirements of the system.According to the simulation results,the circuit of inverter including main circuit,driving circuit,signal sampling circuit and control circuit based on TMS320F28335DSP controller are designed and built.At the same time,the corresponding software is designed.And the feasibility and correctness of the design is verified by the experimental results again.