چكيده به لاتين
Nowadays, due to political focus on environmental issues, global warming and rising global energy demand, renewable energy sources such as photovoltaic systems (PV), wind power, and fuel cells have received more attention. However, some renewable energy sources such as PV and energy storage systems have low output voltage. Hence, research in high voltage gain DC-DC converters has been increasing in recent years. A single-switch high voltage gain non-coupled inductor DC-DC converter is presented in this thesis. The introduced converter achieves high step-up gain without using any coupled inductors or transformers, provides high efficiency and has a simple control system. The converter also achieves low voltage stress on the switch and diodes without clamping circuits, reducing cost, conduction losses and complexity. The input current of the introduced converter is continuous with low ripple, and is therefore suitable for renewable energy applications in which the fast dynamic response of the converter is necessary. The principle of operation and design considerations of the introduced converter are investigated. The proposed converter for 200W output power with 40 kHz switching frequency, 40V input voltage, and 250V output voltage are simulated in Matlab/Simulink, as well as implemented in the laboratory. Then, the proposed converter is used in the two-stage three-phase grid connected photovoltaic (PV) inverters. The active power and reactive power control with the maximum power point tracking (MPPT) for the proposed two-stage three-phase grid connected photovoltaic (PV) inverters are discussed. Finally, the simulation results of the proposed two-stage three-phase grid connected inverters are reported.
