Study On The Photovoltaic Generation Energy Storage System

The usage of non-renewable energy sources has brought serious environmental pollution problems, which affects the development of society and harms the people’s health. The use of Photovoltaic(PV) generation systemwith an energy storage unit has received positive attention because of its proven environmental, social and economic benefits. Additionally, the key technology of the PV system has become a popularresearch topic. The object of this paper is to studythe photovoltaic energy storage system.In this dissertation, the author investigates the control strategy of energy storage in the photovoltaic generation system and optimizes the further structure of the energy storage converter.Based on the analysisof photovoltaic generation system operating characteristics and the features of the battery performance as energy storage, the author conducts the research on the control strategy of the photovoltaic generation system in grid-connected and islanded operation. A simulation test is used to verify the performance of the strategy.In this paper, multiple mathematical models are established: Buck, Boost, and Buck/Boost circuit. The research of this paper focuses on the control strategy of energy storage charge and discharge, maximum power point tracking technology(whichis proposed based on the energy storage unit), and the design of energy storage unit(which is used to implement the photovoltaic generation system power fluctuation and control strategy of energy flow). The simulation tests are conducted to represent the result of previous research.In order to improve the stability of the photovoltaic generation system, a DC bus voltage control method based on phase shifting parallel control is proposed. The advantages of this method are verified by simulation experiments.A 5kW photovoltaic generation energy storage system experimental platform is built to verify the correctness of the related principles. With the designed main circuit parameters and the selected components, the simulation tests verify the operation of the photovoltaic generation system in grid-connected mode and islanded mode. Additionally, the tests verify the control strategy of energy storage,which in turn stabilizes the photovoltaic generation system power fluctuation, and controls the flow of energy. The results have verified the effectiveness of the proposed mode transfer technique for the photovoltaic generation system.