Research On Solar Grid-connected Inverter

As social and economic development, energy reduction and environmental pollution increasingly become the major issues of society. Solar energy resources as a renewable clean energy, it makes people concerned about the photovoltaic technology. Scientific and technological progress, improvement performance of solar control systems, especially in the photovoltaic inverter technology rapid development and cost reduction, makes the worldwide PV industry have broad market prospects. Therefore the study of PV grid-connected inverter has an important significance.In this paper, three-phase grid-connected photovoltaic inverter carried out a detailed study. First of all, set out the principles and the role of boost circuit in the inverter, and describes a variety of control methods of the solar maximum power point tracking. In the photovoltaic system, using the observation and disturbance method makes maximum power point tracking control simple, and have the advantages of fewer control parameters, then analysis its control processes. Next, analysis PV inverter detaily and three-phase voltage source SPWM inverter technology, describes the working principle of three-phase inverter and the work processes. According to the characteristics of PV systems, the grid voltage-type inverter use current control strategies. With current-voltage double-loop control mode, make the system has good control performance. On this basis, island effect were analyzed in the PV inverter systemFinally, on the basis of theoretical analysis and system design, design inverter hardware and software design, which are included the choice of the main circuit power device, filter inductor design, control loop, the sampling circuit, protection circuit, maximum power point tracking control and SPWM software design in the DSP. After debugging the system test and analyzing the experimental results, the correctness and feasibility of the PV inverter system can be proved.Figure [39] table [1] reference [40]...