Reseach On The Key Technology Of The Concentrating Photovoltaic Lighting System

As the environmental protection is more valued, more countries are trying to find new energy sources to replace the normal fossil fuel. The solar energy is getting more and more attention because of its abundance. Now photovoltaic power generation is the main way of using solar energy with a large investment and low efficiency. Meanwhile we consume a lot of electric power due lighting and waste a lot of energy. Concentrating photovoltaic lighting system transmits the sunlight to indoor by optical fibers, saving much electric power used on lighting, it’s a very good way to using the solar energy. Compared with the traditional illumination devices sun- lighting is not only more environmentally friendly, but also conducive to health personnel.The concentrating photovoltaic lighting system designed in this paper is comprised of tracking system, concentration system and transmission fiber. The tracking system is used to track the Solar orientation; concentration system is used to concentrate the solar; transmission fiber is used to transport the concentrated solar energy.The tracking system uses a new type of adjustable precision solar orientation tracker which has a very high precision and can judge the weather is sunny or cloudy, what is more important the tracker can adjust its precision by changing its size. The mechanical operation equipment of the tracking system has two forms: one is the L298 N control the DC motor with a reduction gear worm, the another is based on the PTZ.The concentration system adopt the Fresnel lens to concentrate the solar energy. In order to reduce the temperature of the focal point, the paper also takes a cooling device: an insulated glass and a homogenization lens. The insulated glass is placed before the Fresnel lens to reflect infrared and ultraviolet. The homogenization lens is placed in the focal point of the Fresnel lens. After the sunlight reflected by internal of the homogenization lens, allows sunlight to distribute homogeneously on the exit sur face of the lens. In this paper, the design of the homogenization lens are focused, and we obtain the criterion that the size of the lens should meet, and we also use the optical analysis software Tracepro to simulate effect of the lens.The paper gets the advantages and disadvantages by the comparison of the three conductive fiber. According to the requirements of cost reduction, the system uses a plastic optical fiber as a conductive fiber.At the end of the paper we test the tracking precision of the tracking system, the results show that the tracking system has a very high tracking precision and satisfies the requirement; we test the cooling effect of the insulated glass and the homogenization lens, the results show they work well; finally we test the actual lighting effect of the concentrating photovoltaic lighting system, and the system meet the basic requirement of indoor lighting.