Optimization Of Renewable Energy System Coupled With Energy Storage

Renewable energy has developed rapidly in recent years,which is of great significance in coping with global climate change,ensuring the security of power supply and ensuring the sustained and rapid development of economy and society.However,due to its randomness,volatility and intermittence,large-scale access to the grid will have an adverse impact on the operation of the power system.By constructing a large-scale renewable energy system coupled with energy storage,the energy storage system is used to stabilize the volatility and intermittent of renewable energy and improve the use value of renewable energy.Based on the above background,this paper carried out the research on the optimization of renewable energy system coupled with energy storage.The research contents mainly include the capacity optimization of wind-solar-storage system,the optimal allocation of hybrid energy storage system in wind-solar-hybrid storage system,and the optimization analysis of wind-storage system based on price arbitrage and standby service.From the perspective of demand side response,a multi time scale hierarchical optimization model of movable load is established by introducing load time shift strategy.The model of wind power and photovoltaic output is established by confidence interval method.Under the premise of satisfying the constraint conditions,taking the minimum annual cost of wind-solar-storage system as the optimization objective,and considering the impact of demand side response on capacity allocation,the genetic algorithm tool is used to solve the capacity allocation optimization problem,and the optimal allocation of distributed wind power,distributed photovoltaic and energy storage system is obtained.Through the comparative analysis,it is concluded that considering the demand side response,the user load curve is closer to the distributed generation output curve,which significantly reduces the annual cost of the wind-solar-storage system,and verifies the superiority of the demand side response in reducing the capacity allocation cost of the wind-solar-storage system.Energy storage system includes power type and capacity type.Single energy storage has its own advantages and disadvantages.At present,no energy storage technology is dominant in all performance parameters.Therefore,in the microgrid of distributed renewable energy,the comprehensive utilization of different types of energy storage can not only give play to their advantages,but also make up for their shortcomings.According to the capacity configuration results of the wind-solar-storage microgrid system,the power curve of the source-load difference is obtained.Based on the method of quadratic moving average filtering,the source-load difference power is divided into high frequency,medium frequency and low frequency parts,which are borne by super capacitor,Li-ion battery and compressed air energy storage system respectively.Through case analysis,the rated power,rated capacity and initial state of charge of three types of energy storage systems are obtained.Compared with the single Li-ion battery energy storage system,the hybrid energy storage system can effectively reduce the cost of the system and improve the stability of the system.The addition of energy storage system will inevitably increase investment costs.Therefore,in order to achieve commercial development,it is necessary to carry out the technical and economic research on the coupling system of energy storage and renewable energy.This paper analyzes the economic benefits of the application of energy storage in wind power generation system,and comprehensively considers the influence of factors such as the electricity sales benefits of the wind-storage system,the standby service benefits of the energy storage system and the investment costs of the energy storage system.The optimization model of the wind-storage system and the operation control strategy of the charging and discharging process are established considering both the price arbitrage and the reserve auxiliary service.The annual comprehensive benefits of the wind-storage system under different energy storage and release efficiency,energy storage system cost and energy storage system life are evaluated.The optimal energy storage capacity and the corresponding annual comprehensive benefits of the optimal energy storage capacity are obtained when the annual comprehensive benefits of the wind-storage system reach the maximum under different energy storage conditions.