Research On Optimal Sizing Of Building Photovoltaic-energy Storage System In Harbin

With the global climate worse and the depletion of traditional fossil energy,how to develop and use new energy reasonably has become the focus of the world.The clean energy represented by photovoltaic and wind energy is developing rapidly all over the world and has been widely valued.As distributed energy,they can effectively reduce carbon emissions by converting wind and solar energy into electricity.Compared with wind power generation,photovoltaic power generation is not affected by regional factors and more suitable for distributed development.With the development of lithium-ion battery in recent years,its energy density is increased,its cost is constantly reduced,and the vigorous development of new energy industry,resulting in the combination of distributed energy storage and new energy technology has become a new technology route.The cooperation of energy storage system and photovoltaic power generation system can effectively alleviate the intermittence and instability of photovoltaic output.In the selection of energy storage system components,the cycle life of lithium-ion battery needs to be further improved.Because of its high power density and long life,supercapacitor-battery hybrid energy storage system becomes a reasonable scheme.In this paper,a supercapacitor-battery hybrid energy storage system in buildings has taken as the research object,the system model composed of different components is established,and the cost of supercapacitor-battery hybrid energy storage system is optimized to obtain a reasonable system components sizing.First of all,considering the particularity of annual illumination due to climate reasons in Harbin,China,according to the different components of the system,four scenarios are divided and the system configurations under four scenarios are established.Secondly,a supercapacitor-battery hybrid energy storage system operation cost model is constructed.Taking the capacity of the supercapacitor-battery hybrid energy storage system as the boundary condition,the dynamic programming algorithm is used to simulate and compare with the traditional rule-based algorithm.Taking the minimum annual system operation cost as the objective function,the system capacity and power flow are jointly optimized,and a components sizing method of the supercapacitor-battery hybrid energy storage system is proposed.To consider the effect of battery life degradation due to different charge and discharge rates and charge and discharge times,a semi-empirical model based on the Arrhenius model was used to quantify the battery life degradation.Finally,the optimal capacity allocation of the three is obtained,and through the sensitivity analysis of the composite energy storage system price,the feasibility of the composite energy storage system with photovoltaic system is discussed compared with the pure battery energy storage system.The simulation results show that the proposed method can not only meet the optimal economy of the system,but also effectively take into account the energy storage system life decline caused by irregular charging and discharging,obtain the minimum operating cost of the system,and obtain the optimal capacity configuration of the system.The research content of this paper can provide some basis for the structural design of photovoltaic energy storage system in Harbin buildings.