Research Of The MPPT And PFC Technology In The Solar Hybrid DC Power Supply

With the rapid development of the global economy, the limited fossil fuels such as coal, oil, natural gas have been unable to meet the development needs of human beings, in order to avoid an energy crisis, we must vigorously develop new and renewable energy. Solar energy is a clean, efficient and inexhaustible energy of solar radiation, but the output of photovoltaic cells is affected by the external environment and the load, in order to make full use of solar energy, improve the efficiency of photovoltaic cells, solar power supply systems need to join in auxiliary power and to make a maximum power point tracking of photovoltaic cells.In this paper, a combination of photovoltaic technology, the maximum power point tracking technology and power factor correction technology, developed a set of energy-efficient solar hybrid DC power supply system, it consists of solar pv, battery, AC/DC power supply integration, realize the diversification of energy sources, can be automatically the undisturbed switching. At the same time it also has the MPPT, PFC and real-time monitoring functions. For the solar hybrid dc power supply design, this paper work is as follows:(1) In detail elaborated the basic principles of solar power technology and the MPPT, analysis and comparison of the constant voltage method, disturbance observation method and incremental conductance method three MPPT algorithm, summed up the advantages and disadvantages of each algorithm, proposed a tracking algorithm suitable for this subject-constant voltage start combined with perturbation and observation algorithm. Commonly used DC/DC converter are introduced, and then selected the appropriate conversion circuit and the main control chip based on the actual requirements of the system, completed the design of hardware circuit parameters, selected the appropriate electronic components, made circuit board, to build a120W PV power generation systems.(2) Introduced the basic principles of power factor correction, the main circuit topology and control method of PFC carried out a detailed analysis and comparison, and ultimately determined the suitable for the power factor correction scheme of this system; Boost type APFC based on the average current control. Using UCC28019controller chip designed an APFC experimental circuit based on the average current mode control, the output power of1kW, gave a detailed design steps of PFC circuit and specific parameters calculation process.(3) Studied how to quickly undisturbed switching three kinds of power supply, to ensure that the hybrid power provide stable and reliable electricity to the load for24hours a day, and proposed switching control algorithm, proceeded design for intelligent automatic undisturbed switch controller of solar hybrid DC power supply system.(4) Individually tested MPPT solar hybrid DC power module and PFC module, and analyzed the results of the experiment, and then proceed Integration test to the mixed DC power.