Research And Design On Two-stage Grid Connected Photovoltaic Generation System

There is a growing trend of the global energy crisis and environmental pollution,developing clean renewable energy has become a serious problem facing us. Solar energybecomes the focus in the world with its advantageous characteristics, and PV grid connectedpower generation system is the main trend of solar development. With the rapid development ofmicroelectronics and power devices, solar power technology research has entered into ahigh-speed development period. Under this background, this article conducts an in-depththeoretical research on photovoltaic grid-connected power generation system and simulationexperiment, then designs1KW single phase photovoltaic grid-connected power generationexperimental system based on TMS320F2812. About shading problems appeared in practicalapplication of the photovoltaic power generation system, this paper puts forward a new solution.The main research contents are as follows:(1). The development situation of domestic and international photovoltaic industry issummarized, and several kinds of common topologies of photovoltaic grid-connected generationsystem and MPPT control algorithms are compared with, then analysis their respectiveadvantages、disadvantages and applications. It also sets up photovoltaic array simulation modelin MATLAB, and conducts the simulation research on the maximum power point tracking(MPPT) based on perturbation and observation method.(2). On the basis of analyzing the mathematical model of photovoltaic grid-connectedinverter and the implementation process of space vector pulse width modulation （SVPWM）, Itbuilds single phase photovoltaic grid-connected generation system model based on the dualclosed loop control and three phase photovoltaic grid-connected power system model based onthe power decoupling control strategy, which has been verified by simulation.(3). The hardware of1KW single phase two level PV grid-connected generation system hasbeen designed, which consists of a main circuit and a control circuit, connected by the isolationdevice, and program the MPPT control and the control of grid-connected and off-grid inverter.Inverter control program adopt double closed-loop control strategy, and is verified by experimenton its reliability and stability, which achieve the expected goal.(4). The shading phenomenon is appeared when photovoltaic grid-connected generationsystem is applied in engineering practice. It takes advantage of the particle swarm algorithm in solving multimodal optimization to present a current control type particle swarm multimodalMPPT algorithm, and gives the implementation process of this algorithm. At last, simulationexperiment in the MATLAB/SIMULINK is carried out, and the results show that the algorithmis feasible and more superior compared with the traditional algorithm in MPPT control.(5). Summing up the whole job is undertook, and the further tentative idea of research is putforward．...