Research On Single-phase Photovoltaic Grid Connected Inverter Based On Virtual Vector Oriented Control

Under the pressure of severe energy situation and human ecological environment situation, solar gets more and more attention of countrys in the world as the clearer energy. Grid connected photovoltaic generator is not the limit of energy resources, raw materials and application environment, so it has broad prospects for development, which is the main source of future world energy and electricity. Grid connected inverter is connection interface for photovoltaic power generation system and the grid, so the research on grid-connected inverter control technology has an important meaning, the research work of this paper is as follows:Firstly, this paper introduces the status and trends of domestic and international development of the photovoltaic grid connected system, elaborates the composition of the photovoltaic power generation system and operation mode of the grid-connected inverter. Analyzed to two common single-phase photovoltaic grid-connected inverter control method, and summarized their advantages and disadvantages, then this paper proposed a new control method based on the virtual vector oriented control single phase photovoltaic grid-connected inverter control strategies.Second, low-frequency model and high-frequency model of the virtual vector based on single phase grid-connected inverter are set up in the two phase stationary coordinate system and two phase rotating coordinate system, then analysed the operational status and working principle of the single phase grid-connected inverter, and laid the theoretical foundation for the model simulation. Gives the vector relations and decoupling control scheme based on the virtual vector oriented single phase grid-connected inverter in dq rotating coordinate system, and then designed the current loop calculation steps; and under the MATLAB/SIMULINK environment, established simulation model to the three kinds of current tracking control method, compared simulation waveforms for three control strategies, the conclusion that the correctness of the best based on the simulation results of the virtual vector oriented control strategy. The simulation results verify that the system control strategy.Finally, this paper introduces the design of the TMS320LF2407based on the virtual vector oriented control single phase photovoltaic grid-connected inverter control system. For the control system of hardware and software design makes detailed discussion; including several major hardware circuit design process, and then on the basis of the hardware circuit design system software, the software part including the main programs, periodic interrupt subroutine and fault handling subprograms. The experimental results verify the feasibility and effectiveness of the control strategy.