Renewable energy is an important source of energy production due to the limited fossil fuels and their pollution to the environment. The use of renewable energy sources such as solar and wind energy are essential due to their benefits and availability. Sources such as fossil fuel energy are less used due to environmental pollution. Solar energy has many advantages, including availability and cheapness. Over time, the price of solar cells has dropped dramatically and can be used in many different systems. Solar cells can be used in local loads and power grids. Inverters are one of the most important and costly components of solar systems. In recent years, the use of microinverters in grid-connected and off-grid applications has increased significantly. With the construction of new and cheaper panels, the importance of high efficiency and low cost solar inverters has increased. Microinverters are highly expandable and easy to use, but low output efficiency and ground leakage current are among the weaknesses of these structures. In this Thesis, two single-stage non-insolated microinverter structures are introduced. The first structure is a converter that is the integration of buck-boost and sepic converters. The modes of operation of this converter have been studied and its simulation and construction results have been analyzed and eva‎luated. The second converter uses a coupled inductor, which increases the output gain of the circuit and reduces the voltage of the switches with the help of a clamp circuit. The two proposed structures solve the problems of non-insolated microinverters such as lack of common ground capability, low output voltage gain, ground leakage current and high losses and low efficiency. An important advantage of these two structures is the use of only two high frequency switches to generate sinusoidal voltage. Both structures have been studied and controlled in off-grid conditions and the results have been thoroughly investigated.

مسعود حاجيان

احسان اديب

حميدرضا كارشناس، احمدرضا تابش