A single-phase two-stage grid-connected inverter for solar PV system with maximum power point tracking

With the increasing environmental pollution and energy shortage, countries around the world pay more and more attention to the development and utilization of clean renewable energy, solar energy because of its wide distribution, recyclable, and other characteristics is widely used nowadays, photovoltaic power generation as the main form of solar energy utilization, has also been rapid developed. Photovoltaic gird-connected inverter, as a core component of photovoltaic power generation system, the choice of its topology and control strategy plays a decisive role on the performance of photovoltaic power generation system. This report mainly discusses the topology and principle of this circuit, after that, a high performance single-phase two-stage grid-connected inverter with maximum power point tracking has been modeled and simulated successfully. At the first paragraph, background and some basic knowledge of solar photovoltaic technology are introduced. And then at the second paragraph, literature review has been made to demonstrate some previous research in this area. The third paragraph is the most important part of this report, the model and principle of each part of the inverter has been illustrated separately and what is more, the maximum power point tracking is introduced and implemented in the DC/DC boost converter successfully to ensure the efficiency of the PV panel. Certainly, the results of this inverter will be shown in the paragraph four including the output P-V curve of the PV panel, which shows the work of MPPT, output voltage of the DC/DC boost converter and grid current and so on. Finally, the conclusion and future work will be given in the last paragraph. Master of Science (Power Engineering)