Key Technology Research Of Dense Array High Concentrating Photovoltaic System

High concentrating photovoltaic technology(HCPV)is considered to be the most potential power generation technology to replace the silicon technology because of its advantages of wide spectral absorption range,high conversion efficiency,low efficiency attenuation in life circle,strong adaptability to environment temperature,high land use efficiency in practical application,low energy consumption in the manufacturing process and no pollution to environment.The key factors such as high cost and low practical power generation of module,high cost and poor tracking accuracy restrict the large-scale application of HCPV.In this thesis,to solve those problems,increasing the magnification to optimize high power photovoltaic module and optimizing the structure to improve the accuracy of the tracking system are presented.By adopting the basic theory of non-imaging optics and geometrical optics,Zemax numerical simulation and experimental study,the concentrating system of the higher concentrating multiples modules is studied;By the combination of the basic theory of heat transfer,ANSYS numerical simulation and experimental study,the thermal dissipation system of the higher concentrating multiples modules is investigated;The tracking system is studied by means of driving principle analysis,ANSYS numerical simulation and experimental study;The experimental study of the higher concentrating multiples modules field power generation is carried out by adding the comparison test modules.The main research work of this paper can be summarized as follows:1.The spherical and flat topped secondary optics was proposed and fabricated for the first time,which solved the optical concentrating problem of the higher concentrating multiples modules.According to the current matching principle of the three junction battery,the input spectral range was determined.The optical concentrating system of the higher concentrating multiples modules consisted of Fresnel lens and the spherical and flat topped secondary optics.Through the simulation and optimization,the key parameters of the Fresnel lens and the spherical and flat topped secondary optics were determined.The experimental results show that the concentrating efficiency of 712 X concentrating module system is 86.15%,the acceptance angle is ±0.782°,and the output power change is 3.68% in the temperature range of-20?~50?.The spherical and flat topped secondary optics is simple,easy processing and lower cost than that of the microprism.2.The distributed heat dissipation structure of small copper pieces to aluminum plate and aluminum heat radiating tooth was proposed to solve the heat dissipation problem of higher concentrating multiples modules.The design of the small copper pieces to aluminum and aluminum heat radiating tooth increased the internal air heat convection and improved the chip energy diffusion rate;Embossed glasses increasd the external air natural convection cooling area and improved external heat dissipation rate.Through simulation and experimental results,the key parameters of the internal heat sink radiator with 712 X and 1600 X were determined.The research shows that when the limit temperature is 50?,the temperature of battery chip has not reached 110?,guaranteeing long lifetime,high efficiency and high reliability work of modules.3.The chain tracker system was proposed and fabricated for the first time.The worm gear reducer and the chain drive mechanism ensured the high precision of the drive part.The fishnet type structure and positive and negative buckle leveling mechanism ensured the mechanical properties of tracking system.The results of simulation and actual power generation tests show that the tracking accuracy of the chain tracker system is less than 0.375°,and has higher efficiency than the more common push rod tracker.The cost of the tracker is 1.68 RMB/W,which is the lowest cost tracker system.4.The 712 X dense array concentrating module was developed successfully.The experimental study on the grid-connected power generation efficiency of the 712 X concentrating module was carried out.The actual grid-connected power generation experimental results of the modules in three areas of Jiayuguan in Gansu,Delingha in Qinghai and Nimu in Xizang show that the all-day outdoor power generation efficiency of the 712 X module is almost equivalent to 400 X module,with the good heat dissipation and low temperature performance.The maximum actual power generation efficiency of the 712 X module is 28.2%,which is the maximum value of the current actual generation efficiency of modules.The test results of power generation efficiency combining the 712 X concentrating module and chain tracker system show that the power generation conversion efficiency is about 25.48%,which have a good practical performance.The cost of the 712 X concentrating module is 5.26 RMB/W,a decrease of 33.5%.With the battery to meet the requirements of the 1600 X concentrating module is successfully developed,the cost of the module will be reduced to 2.96 RMB/W,lower than the price of silicon module.