Photovoltaic systems based on power electronic transformer with maximum power tracking capability

In today's world, the tremendous development of science and technology has caused new problems for humans. The non-optimized consumption of fossil fuels may cause irreparable losses (environmental pollution, wide changes in the Earth's climate and The scholars and experts are looking for resources that will gradually replace fossil fuels. The distributed generation (DG) is a growing method for production of electrical energy in electric power systems. In recent years, the use of renewable energy sources in distributed generation systems has been increasing. One of these sources is solar energy. They account for a large share in distributed generation systems day by day. However, given the relatively low voltage of solar cells, there are different ways to connect these resources to load or network. In some cases, low-frequency transformer (50 or 60 Hz) is used to solve this problem. In the other cases, large photovoltaic arrays have been used for this purpose. But, Each of these methods has its own drawbacks. Therefore, considering all the above, an alternative solution to this problem is the use of power electronic transformer (PET) technologies. The power electronic transformers with high-frequency ac link are good alternative to low-frequency transformers. They may mine and transfer power with the static converters in their structure. However, this study aimed to review existing structures and provide a power electronic transformer based optimal structure. PET presented here, consists of three stages, each stage has a separate control system on the need and together can facilitate the transfer of power to the network. It also has the ability to track the maximum power point also.