Optimal Design Of Stand-alone Photovoltaic Power System

Along with the population growth and economic development, the world's energy shortage and environmental pollution is increasing rapidly. There are mainly two ways to resolve this contradiction. First, develop and use new energy, particularly renewable energy resources; second, improve energy efficiency and save energy. In recent years, governments around the world have put forward appropriate energy strategies for sustainable development, and developed many relevant policies to support solar, wind and other new green energy. China is the second largest energy consuming country. Developing PV industry has important strategic significance to achieve stable and healthy sustainable development.At present, China ranks among the world's largest solar photovoltaic product manufacturing base. On one hand, the continuous improvement of materials and processes can increase the photoelectric conversion efficiency; On the other hand, reasonable electrical system design can greatly improve the efficiency in the use of solar energy resources. This paper presents several key points to optimize the design of solar photovoltaic system, such as the matching design of PV system, automatic sun-tracking control to improve solar power generation, maximum power point tracking (MPPT) to improve the efficiency of energy conversion and intelligent battery charging management.According to the characteristics of local solar energy resources, this paper describes details about the matching design of PV system with LED lighting as a load. Combined with the charging characteristics of VLRA battery, this paper uses UC3909 and a PWM interface circuit to design a battery charge controller. Choose STC12C5410AD with A/D converter and PWM output functions as the core controller, combine the trajectory tracking mode with the photoelectric sensor tracking mode to realize real-time sun-tracking, use co-simulation to validate the sun-tracking method and analysis the actual experimental data. At the same time, combine open circuit voltage method with variable step incremental conductance method to track the maximum power point of solar PV cells, use MATLAB/Simulink to validate it and make full use of solar energy. Finally, this paper makes a research summary and points out some improvement directions for further research.