| The problems of Energy shortage and energy crisises become more and more serious in the world. Meantime, the traditional fossil fuels such as coal,oil and natural gas are used so largely that had brought serious environmental pollution because the use of fossil energy emit bad gases such as CO2,SO2,NO2. All of these reasons inspire us explore new energy to get rid of traditional energy shortage problems. People nowadays put more and more emphasizes on the development and using of clean energy.Solar energy is a kind of clean and renewable energy, therefore, light fever and photovoltaic energy technologies are developing rapidly. In photovoltaic system, the grid inverter which contributes to convert the DC generated by photovoltaic array into stable AC is an indispensable chain. By grid connection, the sun energy can flow into electrical power grid which can drive load easily.Recent years, the developments of photovoltaic (PV) grid inverter hardware and the control algorithm have become photovoltaic field research focus center, PV inverter technology achieved rapid development. This paper fully summarizes development situation of photovoltaic inverter at the time being, based on this situation, this paper also go down to study and discuss the key technologies of single-phase photovoltaic (PV) grid inverter.This first chapter describes the worldwide energy crisis, development situation of the new energy technologies and grid-connected solar inverter. Then describes the various structures and characteristics of the grid-connected PV systems, and grid-connected solar inverter developing trends and direction. The second chapter mainly discuss inverter DC Boost DC/DC conversion topology in the PV and the maximum power point tracking (MPPT). Detailed discussions are given about the current PV inverters which commonly used in a variety of DC/DC topologies and their characteristics, then the DC/DC conversion topology, Boost, is selected and a detailed analysis of Boost converter are given, in this way we can establish of mathematical model and simulate in MATLAB successfully. Experimental results show that through using this topology can well satisfy the requirements of small and medium-sized power single-phase photovoltaic inverter DC/DC pressor transform. After working on the principle of photovoltaic panels and output characteristics were analyzed, the various maximum power point tracking (MPPT) were compared, which provides reference for Photovoltaic system to choice the maximum power point tracking technology. The DC/AC inverter topologies commonly used were analyzed and compared, and finally selected as a full bridge circuit H DC/AC conversion topology model, and then concentrate on the power tube drive and protection technology. Design and Create an independent drive capability with 6-channel power MOSFET driver test board, and finally by testing conducted on the test board on the drive circuit is verified by a variety of analysis is correct.The island phenomenon appeard when the inverter connects to the Grid are studied. The reasons of this phenomenon and island phenomenon harm were analyzed. The actual detecting ways were compared and for grid system provided the basis to choice islanding detection techniques after studying the grid system general equivalent model. The pulse width modulation (PWM) and sine pulse-width modulation (SPWM) technology were discussed in this paper. And so on the waveform generating way based on TMSF2812DSP.After that a detailed study of the control strategy and simulation analysis was given. At The last of this paper there are a summary of the work on the paper, and the prospection of the development of PV systems. |
PDF Full Text Request