The Research Of Photovoltaic Energy Conversion Inverter Technology

At present, resources of global fossil energy is scarce, climate change and other environmental pressure increase gradually. The new and renewable energy such as solar energy, wind energy, biomass energy have been used as an important strategic alternative energy source of the governments of the world. China is an energy-poor country, while solar energy with the advantages of the clean, safe, renewable etc, is an effective inexhaustible clean energy, used as new energy applications in the highest, the largest resource potential, and has the development of most promising, strong technology and industry leading role. It is an important and indispensable tool to develop Energy-Efficient Economy. Electrical power, as the world’s most widely used energy, is the cornerstone of human life and progress. Therefore, the study on photovoltaic energy conversion system technology of solar energy into electrical energy is of great significance.This subject is based on the research of photovoltaic conversion inverter power supply technical. Firstly, the application of solar in the domestic and foreign, the classification and the components of photovoltaic power system was introduced, and the energy conversion process of the independent photovoltaic power system, the structure and function of each part were analyzed. Secondly, the inverter circuit and working principle was studied in detail. Finally, single full-bridge was selected as the inverter main circuit.In order to study the MPPT control method, non-linear characteristics of the photovoltaic cell was researched firstly, and a mathematical model was established, then a variety of methods of the maximum power point tracking was analyzed and compared. Finally, Fuzzy PID control was selected as the MPPT method, which was proved by MATLAB simulation, having efficacious control effect; meanwhile, in order to manage effectively the storage battery charging and discharging, the charging and discharging control device was researched to protect the storage battery and save costs. In addition, the charging and discharging characteristics was analyzed, and the double closed-loop control method was chosen to control the storage battery.According to the design goal of system, the boost and inverter parts of software and hardware circuit was analyzed and designed. In determining the system hardware structure, the main circuit system, and auxiliary circuit such as the control circuit, driving circuit, detection and the protection circuit were designed. The DSP TMS320LF2407chip was used as software part to complete the reliable operation between the various hardwares, and implement the deadbeat control algorithm of inverter part.Finally, based on technical parameters, indicators were selected and a prototype was built, then according to the experiments in experimental platform, the power rating for3kW of city electricity was got stably. The validity and feasibility in hardware design and control algorithm of PV inverter power supply was verified by experimental results.