Research On Control Strategy Of Hybrid Energy Storage System In Photovoltaic Microgrid

As we all know,solar energy is subordinate to the category of renewable new energy.And compared with other types of energy,solar energy has many advantages,such as large reserves and no pollution.Over time,human development and utilization of solar energy has become more common.However,solar power generation has large fluctuations in output power and poor anti-disturbance and overload capability.When connected to the power grid,it will cause problems such as power imbalance and poor frequency quality in the power grid.Therefore,in the process of improving and optimizing the photovoltaic power generation system,the energy storage equipment is equipped to complete the construction of the photovoltaic microgrid,and the photovoltaic microgrid is fully utilized,and the system has small inertia,convenient research and high reliability,which can be effective.Solve the above problem.In order to achieve a staged breakthrough in the development and utilization of solar energy,it is necessary to pay more attention to the research and analysis of the related issues of the control strategy of the hybrid micro-grid hybrid energy storage system.This paper first focuses on the photovoltaic microgrid system.Completed the establishment of mathematical models for photovoltaic cells,batteries and supercapacitors,and then summarized and summarized the basic characteristics and working conditions of photovoltaic cells and batteries and supercapacitors respectively.Secondly,in the aspect of maximum power control of photovoltaic cells,the MPPT was analyzed.The mainstream constant voltage method and conductance increment method and disturbance observation method are used,and the improved disturbance observation method is selected as the maximum power tracking algorithm.Finally,the workingprincipleandcharacteristicsofthebidirectionalDC/DCconverterareanalyzed.Then the traditional frequency division control strategy under grid-connected operation is analyzed,and the adaptive fuzzy PI control method and the adjustment frequency division control based on the energy storage element SOC are introduced.An improved frequency division control strategy is proposed..The control strategy can enable various parameters to be automatically adjusted according to the working conditions,so that the effect of suppressing power fluctuations is significantly improved,and the energy storage components can stabilize the corresponding power according to their own characteristics.The battery will stabilize the low frequency part,and the super capacitor will stabilize the high frequency part,which makes the grid connection operation of thephotovoltaicmicro grid morestable.Finally,the working mode of photovoltaic microgrid during island operation is analyzed,and the characteristics of battery and supercapacitor and its SOC limit are combined.Work strategies in different modes were designed and verified by simulation.It is proved that the control strategy can be adjusted correspondingly with different working modes when the hybrid energy storage system isrunning,so thatthe wholemicrogrid isina stableworking state.Figure[58] Table[4] Reference[55]...