Research On MPPT Control Method Of Three-phase Photovoltaic Grid-connected Inverter Based On New Disturbance Observation Method

Solar energy is a kind of clean and environmentally friendly renewable green energy.The conversion of solar energy into electrical energy through photovoltaic power generation is a very important form of utilizing solar energy resources.At present,photovoltaic grid-connected power generation is the main application of photovoltaic power generation systems in the world.Among them,the maximum power point tracking(MPPT)control of the photovoltaic grid-connected inverter and the grid-connected control of the grid-connected inverter are two key technical issues of solar photovoltaic grid-connected power generation.Research hotspots in the field of grid power generation technology.This paper takes three-phase photovoltaic grid-connected inverter as the research object,focusing on the analysis and research of MPPT control method and grid-connected inverter control technology.First of all,based on the analysis of the research status of photovoltaic grid-connected power generation technology at home and abroad,the main research content of this article is determined.Second,the mathematical model and output characteristics of the photovoltaic cell are analyzed and studied,the mathematical model of the boost chopper(Boost)circuit is established,the parameter design method is described,and the mathematical model of the three-phase grid-connected inverter is built,and The PI parameter setting method of current inner loop and voltage outer loop is given.Third,the basic principles of maximum power tracking in photovoltaic power generation systems are studied,and the five common MPPT methods and advantages and disadvantages of photovoltaic power generation are analyzed and introduced.Differential following problem,a new perturbation observation method is proposed to solve this problem,the control strategy of the new perturbation observation method is elaborated in detail,and related simulation research is carried out.Fourth,the overall design scheme of the MPPT inverter controller is proposed,and the main hardware circuit and software program flowchart of the three-phase photovoltaic grid-connected inverter system with TMS320F28335 as the core are designed.Finally,for the MPPT control strategy of the new disturbance observation method proposed in the paper,MATLAB / Simulink software is used to simulate and model the three-phase photovoltaic grid-connected inverter system.The simulation results show that: the new disturbance observation method MPPT control proposed in this paper The method can track the maximum power point quickly and accurately,especially under the conditions of sudden light changes,etc.,and can achieve the maximum power tracking.It has good dynamic performance and steady-state performance,and the effect is significantly better than the traditional disturbance observation method.