Single Phase Photovoltaic Grid Connected Inverter System Based On DSP28335

With the increasingly serious problem of global energy and environmental pollution,the demand for renewable energy is becoming more and more urgent.Photovoltaic power generation has been widely concerned around the world for its clean,pollution-free and sustainable.The development of single phase photovoltaic grid connected inverter system has been paid more and more attention.It is very important to improve the operation efficiency of power generation system and ensure the stable operation of the system.To solve this problem,this paper studies the relevant research,including the following points:(1)On the basis of analyzing the principle,mathematical model and output characteristics of photovoltaic cells,the traditional maximum power point tracking algorithm is studied,on this basis,a new algorithm is proposed——Maximum power point tracking method based on constant pressure method and modified variable step incrimental condustance method.The simulation results show that the new algorithm can improve the speed and stability of the maximum power point tracking by using MATLAB software;after comparing the advantages and disadvantages of PWM modulation,To determine the level of inverter using unipolar frequency doubled SPWM(sinusoidal pulse width modulation)technology,voltage and current double closed loop proportional integral feedback control strategy.(2)The overall scheme of the single phase photovoltaic grid connected inverter system is designed,and the first stage boost is combined with Boost circuit and push-pull circuit.The maximum power point tracking is realized in the Boost circuit and the storage battery is charged,the push-pull boost circuit transfers the battery voltage to about 350 V to the full bridge inverter circuit.(3)The design of system hardware circuit,including Boost circuit,push-pull circuit,DC/AC full bridge inverter circuit,drive circuit,LCL filter circuit,voltage and current sampling circuit,zero crossing comparison circuit and protection circuit.Using DSP28335 as the control chip,using CCS3.3 software to program and debug the system.(4)An experimental prototype is developed,and the related experiments are carried out,the experimental waveforms of the acquisition system are observed by using the oscilloscope and other experimental instruments,and the quantitative analysis is carried out to verify the rationality of the single-phase photovoltaic grid connected inverter system designed in this paper.