Research On Performance Of High Efficiency CdTe Thin Film Solar Cells And MPPT Control Method

To meet the new requirements of global energy and environmental protection,clean and renewable energy such as solar energy is developing rapidly.Photovoltaic power generation systems are widely used in the transportation field,such as the charging posts of the new-energy vehicle,solar cars,solar ships,and traffic/railway stoplights etc.The photovoltaic industry has ushered in a golden period,and China has become the largest photovoltaic producer in the world.At present,the main problems of photovoltaic power generation system are the low conversion efficiency of photovoltaic cells and the high production costs.It is of great significance for the technology innovation of photovoltaic industry to break through the technical constraints and reduce the costs.Supported by Key Science Project of National Natural Science Foundation of China,Problems of CdTe Thin Film Solar Cells with High Conversion Efficiency and Preparation of Batteries(51272247),and four Hubei provincial photovoltaic projects,The thesis is dedicated on the study of CdTe thin-film solar cell power generation system.Focusing on the core technical issues of photovoltaic power generation systems,the performance of CdTe thin-film solar cells and MPPT control methods were studied.A CdTe thin-film solar cell mathematical simulation model was established to optimize the design scheme.Meanwhile,an MPPT logic control algorithm suitable for CdTe thin-film solar cell power generation systems was proposed.The algorithm was verified and the simulation results showed that the stability and efficiency of the photovoltaic power generation system were improved significantly.The main work and the innovative results obtained in this thesis are listed as follows:Firstly,to cope with the problem of low conversion efficiency of CdTe thin film solar cell,a method of doping Cu into CdTe thin film was proposed to improve the efficiency.The performance of CdTe thin film solar cells with doping copper was tested throughout the experiments.Under various experimental tests,this new material shows great performance under the weak light.Secondly,to cope with the problem of MPPT control method,this thesis studied and built the CdTe thin film solar cell model under various illumination intensities and temperature conditions.The model was built in Matlab/Simulink and the output characteristic of CdTe thin film solar cell was simulated and studied.Thirdly,according to the requirements of MPPT evaluation index,MPPT logic control method of CdTe thin film solar cell was proposed.Based on mathematics model of CdTe thin film solar cell,the simulation of MPPT logic control method of CdTe thin film solar cell was emulated and compared with the MPPT conductance incremental method.The simulation results show that the CdTe thin film solar MPPT logic control method improves dynamic and steady-state performance.Lastly,the MPPT control test platform for CdTe thin film solar cell power generation system was set up and the MPPT control method of CdTe thin-film solar cell power generation system was proposed.The experimental research of MPPT logic control algorithm for CdTe thin-film solar cell generation system was carried out.Furthermore,the practicability and effectiveness of CdTe thin-film solar MPPT logic control algorithm were verified.This thesis focuses on the overall CdTe thin-film solar cell photovoltaic power generation system.A number of key technologies in the system have been explored in the fields of theoretical research,computer simulation,and experimental platform construction.The performance and MPPT control methods for high conversion efficiency CdTe thin-film solar cells have been studied.A MPPT control test platform for CdTe thin-film solar cell photovoltaic power generation system was developed.Through comparative experiments,the experimental results justify the theory and simulation research.The research results give insights on the theoretical and technical study for the design,preparation of CdTe thin-film solar cells and the development of corresponding CdTe thin-film solar cell power generation systems.