Design Of Solar Cell LED Lighting System

With the development of social economy, fossil energy is scarcity, therefore the development and utilization of new energy is becoming general trend of the world.In numerous new energy, solar energy as an inexhaustible supply of clean energy gets the world’s attention. photovoltaic power generation is one of the main ways to use solar energy, today’s photovoltaic production are increasing every year, the output of our country’s photovoltaic industry have already reach more than60%of the global photovoltaic industry in2011, but the application of photovoltaic products is still mainly in Europe, Japan and the United States, therefore we need to increase the intensity of researching and developing in photovoltaic products. For the lighting industry, LED is called the fourth generation light source, with the advantage of high efficiency and energy saving, which bring huge influence to the energy shortage of the society.In the electric power industry, lighting occupies considerable proportion, so it is significant for energy poor society to combine photovoltaic technology and LED together.Based on consulting large amount of related documents about solar lighting system, we combined basic principle of solar cell and basic structure of solar lighting together, using maximum power tracking technology of solar cell to improve the utilization efficiency of the solar. In addition, we analyzed the charge and discharge characteristics of Valve-Regulated Lead Acid Battery deeply, selected special charger UC3909which has four phase charge properties, and conducted stability study for charging process of UC3909in the frequency domain to prolong its service life. On the basis of deeply understanding the light-emitting principle of LED, we chosen one kind of LED driver which has constant-current characteristics, it can achieve good drive of LED and at the same time can realize PWM dimming of LED. As a core of the entire lighting system, MSP430F149used as a controller can detect the voltage and current of the whole system and implement maximum power point, adjust the PWM of LED lighting and start or close system. Experimental results show that each part of the system running well and arrive expected result of the experiment. Finally, we built some circuit of the system, analyzed the result of the experiment, and the results show that the system design is correct.