The Research And Applicantion Of PV-LED Tunnel Auxiliary Illumination System

For the specific technical requirements and standards of auxiliary illumination system of entrance and exit section in tunnel, especially its brightness changes automatically with the intensity of sunlight outside the tunnel, then a new method of PV-LED tunnel auxiliary illumination system is proposed in this paper. This system is in the view of system reliability affected by complex mechanical structure in the early sunlight conveyor. Furthermore, rising cost with battery and other practical application problems of the traditional PV-LED illumination system are taken into account in this system. The new method not only maintains the adaptive advantages of the sunlight conveyor, but also solves the technical problems of high cost and poor reliability effectively, which has already achieved the intended purpose. Besides, it improves the solar efficiency effectively by the research and application of power generation with scattering sunlight and others. The main works of this paper are as follows:(1)The related characteristic of tunnel illumination system is researched.Tunnel illumination system includes basic illumination system and auxiliary illumination system. The basic illumination system works continuously to ensure traffic safety in tunnels, however, the auxiliary illumination system is applied to save the electrical energy, based on eliminating the "black hole" and "white hole" caused by the overlarge brightness gradient of entrance and exit section in tunnel; Therefore, its work status is relevant to the presence or absence of sunlight and the intensity of sunlight, and it is always under a controlled status.(2) The program of PV-LED tunnel auxiliary illumination system is proposed.By comparative studies on the strengths and weaknesses of three different solar illumination systems applied in the tunnel auxiliary illumination system, a high-reliability PV-LED tunnel auxiliary illumination system is proposed in this paper based on market demand. And it is a simple auxiliary illumination structure which is use PV modules as power to drive LED lighting directly.The brightness of new auxiliary illumination system is still synchronized with the sunlight intensity, and poor work stability of the sunlight conveyor causing by the weather changing and presence&absence of sunlight has been avoided effectively. Moreover, there is a sharp fall in the system cost for not configuring accumulator. And the system reliability is improved greatly without using the tracking unit.(3) Experiment of PV-LED tunnel auxiliary illumination system in cloudy or rainy days is researched.This paper has done further discussion, testing and research about photovoltaic effect of scattered sunlight and how to apply the power in cloudy and rainy days. Moreover, it also uses the quantitative analysis to research the electricity availability and interaction regularity between generation parameters of photovoltaic panels and light intensity under abnormal sunlight. Also, the corresponding control circuit is applied in this system, it does detection of outside tunnel light intensity and compares it with threshold value. Then, then the data is processed by the STC12C5A60S2, switch signal is output to control switching relays. So optimal controlling of power is achieved under different weather conditions, which realizes power generation by taking full advantage of scattering sunlight and improves the solar efficiency.(4) Improved system is designed..The output power can not meet the requirements when the space size is not enough for installing the PV panels, the function of PV panels to track the sun automatically is must be designed additionally based on the former system. And the illumination power requirement is met by the improving solar efficiency. Hybrid tracking method for the photovoltaic solar panels to track the sun is designed, including U-mechanical structure and concentrating adjustable& complementary optical signal sensor and others which are designed specially. So the solar efficiency is improved for 28.3% and the technical support for further popularization and application of this system is provided.The researched and designed PV-LED tunnel auxiliary illumination system is applied in the Huang Shan Yu Tai tunnel’s entrance and exit area and the desired goal is achieved. Compare to the normal PV-LED tunnel auxiliary illumination system, the reliability is improved and its cost is decreased, also, solar efficiency of this new system is improved effectively. In view of technology, it paves the way for the further promoting application of solar energy in the field of highway tunnel auxiliary illumination.