Research On Control Strategy Of Energy Storage System Based On Photovoltaic Output And Load Response

With the rapid development of today’s society,energy demand gradually increased,solar power has been widely used in people’s production and life.However,due to uncertain factors such as weather and temperature,the power generation will fluctuate,affecting the stability of system operation and power quality.At the same time,the instability of load-side power consumption will also reduce the photovoltaic permeability and lead to fluctuations in the system.Therefore,it is necessary to introduce energy storage system as its energy buffer to improve power quality and system stability.In this paper,a photovoltaic power station in Benxi City is ta ken as an example to design an energy storage system for photovoltaic output and load forecasting.The reasonable charge and discharge control of the energy storage system is carried out by adjusting the time constant,and the effectiveness of the power distribution strategy based on energy prediction is verified and analyzed.The research has certain theoretical significance and practical application value for the effective utilization of photovoltaic energy storage system.In this paper,the principle and model of photovoltaic power generation system are studied based on the investigation and analysis of the development status of energy storage technology,and the energy storage system is designed and analyzed according to the basic situation of a photovoltaic power station in Benxi City.The system selects lithium battery and super capacitor as the energy storage medium,and studies the working principle of hybrid energy storage system according to the characteristics of the two energy storage components.Secondly,the historical power generation data of a photovoltaic power station in Benxi City are analyzed,and the factors affecting the photovoltaic output are extracted.Based on the least squares vector machine algorithm,the photovoltaic output prediction model is established to predict the short-term photovoltaic power generation of the power station.Based on the application of the least squares vector machine algorithm,the grey correlation analysis method is introduced,and the factors affecting the load power are extracted as the input of the model.The load forecasting model is established to predict the load in the short term.In this paper,the state of charge(SOC)partition limit power allocation strategy is introduced for photovoltaic output a nd load forecasting,which is used to reasonably charge and discharge control of hybrid energy storage system.Finally,based on the photovoltaic power generation data and load demand of Benxi City,the energy storage system and its control strategy are simulated and verified to ensure that the control strategy can improve the operation stability and efficiency of the system.This paper selects the power and load demand data of photovoltaic power station in a town of Benxi City to verify the effectiveness of hybrid energy storage system control strategy.The simulation results show that the prediction error of photovoltaic power and load is within the national standard requirements,and the prediction error of photovoltaic output in the morning and evening is generally higher than that at noon.When the SOC partition limit strategy is introduced into the system,the output power fluctuation of the energy storage system is reduced by 8.1 %,and the operation stability of the system is improved.By comparing the SOC changes of supercapacitor before and after the introduction of the control strategy,it is verified that the SOC partition limit strategy based on energy prediction can control the charging and discharging of energy storage system more pertinently,improve the working efficiency of energy storage system,reduce the number of lithium battery charging and discharging,and improve the reliability of energy storage system.