Study On Solar Photovoltaic System With The CLFR Concentrator And High Solar Concentration Uniformity

Solar energy utilization is one of the most effective approaches which can solve the sustainable development problem in the future.Traditional solar concentrators can only form low solar concentration uniformities on solar cells.That will lead to the non-uniform temperature distribution and local overheating on solar cells,resulting in the efficiency decrease of photovoltaic(PV)modules.Hence,the design of solar concentration photovoltaic(CPV)system with compact linear Fresnel reflector(CLFR)concentrator and uniform concentrated energy flux density as well as the studies of optical performance and energy conversion efficiency of the CPV system has some scientific significance for improving the photo-electric transformation efficiency and promoting the development of solar PV power technology.In this paper,a solar CPV system with high solar concentration uniformity is proposed.The relevant theoretical analysis,simulation study and experimental research are launched.The works conducted and main conclusions include:Firstly,the design approach of the solar CPV system with CLFR concentrator and high solar concentration uniformity is provided.A comparison analysis of structural parameters,optical parameters and solar concentration uniformity of four CPV systems are launched,including a CPV system using the complete-type CLFR concentrator and three CPV systems using different hybrid-type CLFR concentrators.The results demonstrate that the solar CPV system using the complete-type CLFR concentrator has the largest geometric concentration ratio,highest ground utilization ratio and highest solar concentration uniformity.Secondly,the optical characteristics of the solar CPV system using the complete-type CLFR concentrator is investigated.The influence analysis results of the sun-tracking error reveal that with the sun-tracking error increased,the overall optical efficiency of the solar CPV system using the complete-type CLFR concentrator decreases linearly.When the deviation angle increases to 0.20 and 1.00,the normalized overall optical efficiency of the CPV system decreases to 89.0%and 45.0%,respectively.The interactions between key structural and optical parameters of the solar CPV system using the complete-type CLFR concentrator is analyzed.The results indicate that when the concentrator mirror field width,slope angle and width of solar cells are settled,or when the total number of mirror elements,concentrator mirror field width and solar cell width are settled,the concentration ratio and ground utilization ratio both increase first and then decrease as the solar cell height increases.The optimal solar cell height exists,which can lead to the maximum concentration ratio and ground utilization ratio simultaneously.Finally,the experimental set-up of solar CPV system using the complete-type CLFR concentrator is developed.Based on this device,the solar concentration uniformity test of the solar CPV system using the complete-type CLFR concentrator is carried out.The results reveal that the CPV system has relatively high actual solar concentration uniformity.Certain differences between the experimental and simulation results exists but a good agreement between the experimental and simulation results is also demonstrated.The preliminary I-V characteristics tests of the monocrystalline silicon PV cell monomer and module installed in the experimental set-up are launched.The results indicate that the photo-electric transformation efficiencies of the PV cell monomer and module are 16.9%and 15.9%,respectively.