Research On Control System Of Grid-connected Photovoltaic (pv) Based On The Flow-through Networking Technology

With the shortage of fossil fuels and serious environment problems, in order toresolve the crisis, people continuously try to exploit green renewable energydevelopment and utilization of new theory and new methods. Solar photovoltaic powergeneration will help ease the energy shortages also helps prevent both environmentaldegradation, thus become a hot academic research direction of the electrical engineering.With the constant progress of power electronic technology, automatic controltechnology and falling production costs for photovoltaic cells, solar photovoltaic powergeneration from complementary energy into alternative energy sources are possible.With the continuous improvement of power and power density, parallel operation willbecome the most main operation mode of photovoltaic power generation.The countercurrent grid solar micro-grids no opened up a new way of thinking tothe use of solar energy. It belongs to Not scheduling type,this power does not requirebatteries and other energy storage devices, not only to avoid the batteries pollute theenvironment, but also improve the utilization rate of photovoltaic power generationsystem. Ensures that the output of the photovoltaic power generation system powerpriority to load power supply, and municipal power grid as a backup power to supply.Combined with this feature, This paper proposes a grid-connected photovoltaic (pv)based on the technology of flow-through networking topology structure of the controlsystem, and the control strategy of the system, hardware and software design carried onthe thorough research.1. First of all, studied the photovoltaic principle, structure of photovoltaic powergeneration system are analyzed, the influence of the grid to its distribution network andthe key technology involved;2. Secondly, studied the working characteristics of photovoltaic (pv) grid system, theworking principle of three-phase grid inverter is analyzed in detail,and the main circuittopology structure is determined. The mathematical model of inverter in the two-phasestatic coordinate system and rotation system are presented. From the inverter controlmode, the inverter control model of inverter are analyzed, the grid inverter controlstrategy is determined. Further study of the SVPWM control technology and phase lockloop technique.3.In hardware aspect: first, to build the overall framework of the system, and thenseparately for each part of circuit and its parameters has carried on the detailed design,control circuit chip is chosenTMS320F28335;In software aspect: first, design the controlsystem of main program and period interrupt subroutine, again to interrupt subroutine,such as fault detection and processing, software phase lock, A/D subroutine, SVPWMsubroutine, and protection of the interrupt subroutine are discussed;4.Finally constructs the system simulation mode based on MATLAB/SIMULINK,Simulation results verify the feasibility of the proposed control strategy.