Algorithm Research Of Maximum Power Point Tracking In Photovoltaic Power Generation System

With the increasingly serious energy crisis,renewable energy has naturally attracted people's attention,how to develop renewable energy better has become a global issue.As one of the renewable energy sources,solar energy is favored because of its advantages of cleanliness and huge reserves.Photovoltaic power generation,as one of the main forms of solar energy resource utilization,has many advantages,such as inexhaustible uselessness,no need for transportation,and availability of local materials.However,due to the non-linearity of the voltage and current curves of photovoltaic cells,the output power of photovoltaic cells also changes with changes in the external environment such as light and ambient temperature,so how to quickly and accurately track the maximum power point of the photovoltaic curve is still a problem to be solved,Maximum power tracking as an essential part of improving the conversion rate of photovoltaic cells,it plays an important role in the whole photovoltaic system.This paper aims to maximize the use of solar energy resources and carried out research on the maximum power tracking algorithm for an independent photovoltaic power generation system.Firstly,the main components and classification of photovoltaic power generation system are introduced in detail,the working principle of photovoltaic cells is analyzed,the equivalent engineering mathematical model of photovoltaic cells and its equivalent circuit are established,and the output characteristics and mathematical analytical expressions are analyzed.Secondly,the DC/DC topology structure is introduced.The principles of boost,buck,buck/boost and cuk four kinds of commonly used chopper circuits are introduced in detail,and the related formulas are deduced.The classical MPPT control algorithm is introduced.Based on the analysis of the principle of maximum power tracking,five classical algorithms such as constant voltage method,disturbance observation method,conductance increment method,fuzzy control method and sliding mode control method are theoretically performed.At the same time,other MPPT algorithms such as current sweep method,ripple control method,load current/voltage maximum method,and hysteresis comparison method were briefly introduced.Based on this,the Lagrange linear interpolation power prediction used in this paper was proposed,based on this algorithm design the hardware and software part of the system.The relevant software part of the MPPT system is designed by TMS320F28335 DSP,including the design of the main program and the design of three interrupt programs,which are the protection interrupt subroutines?A/D interrupt subroutine and MPPT interrupt subroutine.The hardware circuit is designed based on dc/dc transform circuit,including the design of the main circuit,the design of the drive circuit,the photovoltaic cell output voltage,the design of the current sampling circuit and the design of the AD protection circuit,and the inductor,capacitor,resistor load,MOSFET Switching and other parameters of the selection and calculation.Finally,this paper compares the algorithm with the related traditional algorithms based on the MATLAB/SIMULINK simulation platform to verify the superiority of the algorithm,build the experimental platform,calculate the experimental parameters and design the experimental scheme,and verify the superiority of the proposed algorithm through experiments.