Development of solar energy system for domestic applications

The development of civilization can be tracked directly by the facilities, methods and intensity of mankind's use of energy. In order to be able to do human beings are in need of energy and as a phenomenon that becomes clear after the industrial revolution, the size of this need and the variety of qualities have increased considerably. Most of the current electric energy production is provided by hydrocarbon-based fuels. These resources are limited on earth and the effort and expense required to obtain the remaining reserves is constantly increasing. Conversion efficiency of them are limited and they has significally irreversible damage effects on the environment. For this reason, although the share of renewable energy sources in electricity generation is still low, the rate of increase of the ration of usage of these methods is higher than the hydrocarbon based energy production. Photovoltaic systems can be installed in the form of large-scale power plants for feeding network , as well as suitable applications for domestic use as the focus of this study. Domestic photovoltaic systems collectively can gain significant shares in energy supply. However, since domestic applications will be installed close to the load, losses from traditional large power plants and long transmission lines can be reduced to the greatest, and these systems can be an effective alternative where the network has not yet reached. In this thesis, a off-grid photovoltaic systems is proposed and simulation study is carried out. A total of 12 panels, consisting of 6 serial and 2 parallel arms, are used in the system. The photovoltaic array consisting of panels is mathematically modeled. The boost DC-DC converter is used at the output of the panels. This converter is controlled by the perturb and observation method (P&G) which is one of the maximum power point tracking methods. Thus, maximum power can be drawn from the panels for different radiation and temperature values. The system includes the battery as an energy storage unit. Energy produced in panels more than the demand of the load is stored in batteries. The bidirectional DC-DC converter is used to control the bi-directional energy flow between the battery and the DC bus. Thus, the charge and discharge current of the batteries were kept under control. At the output of the system, a single-phase full-bridge inverter is used to meet the energy demand of the AC load. With the LC filter at the outlet of the inverter, a load voltage of 220 V and a frequency of 50 Hz is obtained. The radiation and temperature values of the panels have been changed in order to demonstrate the performance of the system under different conditions. By applying different values, the balance between the energy production of the panels and the energy demand of the load has been changed and the charge and discharge conditions of the battery have been observed. In addition, the overcharging and over-discharge of the batteries and the response of the protection algorithms in these cases have been examined. At the end of the study, it is seen that the proposed system would be sufficient to provide the electrical energy demand in a non-network area. The system has not been dimensioned within the scope of the thesis study. In order to meet the energy needs of the load continuously in the applications to be performed in the field, panel power and battery capacity should be selected at appropriate values.