Re Search On Maximum Power Point Tracking In Photovoltaic System

The energy crisis and environmental pollution have become the problem which human can’t ignore. Countries in the world have put more and more attention on the development of new energy. The photovoltaic has a lot of advantages, such as huge reserves, clean, so it comes into the major research new energy. Photovoltaic (PV) power generation is an effective way of using solar energy. However, the main factors preventing its expanding are maximum power point tracking, sun attracting, storing energy technique and so on.This paper studies Maximum Power Point Tracking (MPPT) in the algorithm. From improving tracking step sizes and adding a decision part of local maximum power, it can make tracking speed up and avoid wrong judgment, also improve the photoelectric conversion efficiency.This paper mainly includes the following aspects to research MPPT:1. Overview the overall scheme. This thesis firstly expounds the development in the world and mainly parts of PV system. Then propose the research plan of the PV MPPT system.2. Build solar cells mathematical model and simulate. The simulation model of PV module is based on Matlab software. Also research its working principle, output characteristics and the influencing output factors. Then gain PV cells changing rules in changing environment, which can provide a theoretical basis for new variable step size MPPT.3. Propose a new variable step size MPPT algorithm. Analysis and explore some existed MPPT ways, make them better and get a new variable step size MPPT, which mends the questions about step size and local maximum power. This new way improves the photoelectric conversion efficiency of the system.4. Design the hardware circuit and the software of MPPT control system. Simulate it in Matlab. The results verify the new algorithm feasibility.5. Build a MPPT platform and do some related experiments. Contrast New MPPT method with existing tracking algorithm in the comparative tests (fast changing environment, the fixed step size, etc.) under different sets of conditions, gain a lots of experimental data.The results can prove the excellent of new variable step size MPPT in different conditions.6. Summary the main work in this paper, and make some personal views about future MPPT research.