Research On Power Load Optimal Scheduling Based On User-side Energy Storage System

With the sustained and rapid development of our national economy,the electricity consump-tion of demand side will increase gradually,which leads to the imbalance between supply and demand in power systems.A series of documents published by the State Council and the National Development and Reform Commission confirm that the power grid will gradually liberalize the demand side and the electricity price is bound to be flexible,precise and personalized in the future.With the continuous pursuing of Chinese power system reform,the structure of power grids will be changed,which allows energy consumer to play an active role in power system operation and elec-tricity markets in order to reduce their electricity expenditures and increase economic benefits.As an important technical support for balancing power supply and demand,energy storage technology makes great progress in recent years.Energy storage technology such as battery energy storage technology,runs through the process of generation,transmission,distribution and consumption in power system,which can effectively realize demand side management,power load smoothing,equipment utilization improvement and electricity cost reduction.The user-side energy storage systems,which have no electricity dispatching and electricity market at the beginning of develop-ment,usually are small monomer projects.They have the advantages of being close to power users and being more conducive to solve the current supply and demand balance problem of power grid.For individual user,there is no mature business application model of user-oriented energy storage system in domestic.Meanwhile,due to the high initial investment and maintenance cost of energy storage system,researches on optimal sizing and diversified application modes with electricity price and electrical load characteristics are necessary.Based on the challenges afore-mentioned,this thesis takes the user’s power load as the research object with demand charge in European and American electricity markets and studies the scheduling problem of the battery en-ergy storage system.The main contents of this paper are organized as follows:Firstly,based on the existing energy storage system hardware platform,this thesis propos-es the distributed energy management system structure that fits the current grid architecture with some basic functions including system framework designing,load clustering,load forecasting and scheduling algorithms and software implementation.This scheme has been verified on the hard-ware platform and applied in practical commercial scene,which fills the gaps in commercial appli-cations of energy storage systems in China.Next,this thesis proposes a research idea that divides the whole battery into main capacity and backup capacity to optimize different application scenarios respectively.With the purpose of maximizing the user’s comprehensive profit,a mixed integer linear programming model consid-ering the investment cost of energy storage system,demand charge,optimal scheduling and load forecasting error are presented and solved to optimize the best size of energy storage system.Finally,this thesis proposes basic models for sharing storage in power system,which draws on the concept of sharing economy.Based on the centralized management and collaborative op-timization of energy storage system,these models integrate fragmented energy storage resources,improve the energy storage system utilization and optimize user’s maximum demand charge.Fur-thermore,this paper proposes a two stage optimization problem considering the principle of win-win situation of users and power grid in multi-user and multi-energy storage sharing mode.This algorithm could reduce the peak and valley difference and improve the stability of the power grid.