Study On The Frsnel Concentration Photovoltaic System Based On The Principle Of Non-imaging

With the rapid development of society economy, the growing shortage of theconventional energy resources such as oil, coal and natural and the deterioration ofnatural environment are seriously restricting the development of the society world.For these reasons, we must enhance the sense of crisis, establish a green, low-carbonand environmental friendly development concept, focus on energy-saving andemission-reduction, vigorously develop renewable clean energy and then acceleratethe construction of a resource-saving and environment-friendly society. Solar power isa kind of renewable and clean energy with most extensive distribution and maximalreserves. Photovoltaic power generation is one of the main ways to generate electricity,but owning to its low efficiency and high cost, it failed to fully enter the market.Utilizing cheap optical elements to concentrate the sunlight on a smallconcentrated photovoltaic cells is a effective way to reduce the cost of photovoltaicpower generation and increase the conversion efficiency of the photovoltaic cells.Concentration system is the critical element of the photovoltaic power generationsystem, which determines the efficiency and cost of the photovoltaic powergeneration. The Fresnel concentrators have the characteristics of small size, lightweight and low prices, this can make the micromation, integration and intelligenceof the optical system be realistic.With the supports from CAS Innovation Program and the "973" ProgramNo.2010CB227101, the design and photovoltaic concentration test system of theFresnel concentrators are thoroughly studied. This article first utilize the law of reflection and refraction to derive an generate design formula of the Fresnelconcentrators, with this formula, we design two conventional concentrator systems:one is equal in tooth depth; the other is equal in width, and we also simulate andanalyze the spotlighting characteristics thorough the Tracepro software, the resultsindicates that the energy distribution of the conventional Fresnel concentratorsconcentrated spots are not homogeneous, this will make the surface of thephotovoltaic cells partially over heated and therefore reduce the conversion efficiencyof the photovoltaic cells, may even damage the photovoltaic cells. In order to solvethe above problem, this article design a new Fresnel concentration system with auniform energy distribution thorough the non-imaging optical theory and dispersionfocal spot design method.In addition, we design and validate the outdoor concentration test system, withthis system, we test the concentratino characteristic of the conventional Fresnelconcentration system. The test results are close to the theoretical analysis results,which prove the reasonability of the outdoor concentration test system. Although theoutdoor concentration test system have the properties of ideal spectrum and intensitydistribution, it's difficult to precisely measure the concentration system owning to theinfluence of the external weather and environment changes. To solve this problem, weredesign and validate a indoor spotlighting test system, and also proposed a newmeasuring method called discrete spectrum partial measurement method. The methodcan examine the partial production quality of the Fresnel concentrators, and be able toeffectively evaluate the performance of the concentration system. Utilizing the indoorconcentration test system and the discrete spectrum partial measurement method, wetest the conventional Fresnel concentration system of equal tooth depth, the testresults are close to the theoretical simulating results, and also the test results are stableand reliable. The above experiments prove that the indoor concentration test systemand the discrete spectrum partial measurement method are scientific. In order tofacilitate the processing and analysis of the test results of the Fresnel concentrationsystem, we compile the analytical program module of the concentration testexperiment based on the MATLAB language, this program has strong graphic outputfunction, is easy to use and has high efficiency.