| In recent years, Because of the advantages of solar photovoltaic power generation, clean, safe, convenient and efficient, It has become one of the focus of the development of the world renewable energy. As a decisive role in the photovoltaic power generation, The PV inverter is an important part of the photovoltaic power generation system, It has become the focus of research in this field.First, introduce the main classification of photovoltaic inverter, and analyzes the advantages and disadvantages of each kind of topological structure, which leads to high frequency isolation type photovoltaic inverter has the advantages of small size, light weight, good safety and other unique advantages.Secondly, in the photovoltaic power generation system, many domestic and foreign scholars have developed a variety of high-frequency grid connected photovoltaic inverter based on high frequency link technology. This paper chooses the DC/DC transform (DC/HFAC/DC/LFAC) topology structure as the research focus, using sine pulse width modulation (SPWPM) of the new modulation method, and the mathematical derivation and proof of principle SPWPM. Due to the loss of the traditional hard switching in high frequency work becomes a big problem, joining the LCL resonant soft switch, effectively reduce the switching loss. The control method of PV array maximum power point tracking and the grid current loop completed grid connected photovoltaic power generation system. Based on the above theoretical research, this paper designs the hardware circuit of the whole LCL resonant high frequency isolation type photovoltaic power generation system. Including the main power circuit board design, MOSFET power device drive circuit, high frequency transformer, low pass filter etc..Finally, The system is verified by simulation and experiment, the system closed loop high frequency isolated photovoltaic inverter control achieve. It verified the feasibility of the proposed control strategy. |
PDF Full Text Request