The Study On Power System Day-ahead Operation Optimization With Wind-storage Unit

The worldwide energy and environmental crisis has accelerated the pace of developing new energy generation technology.In recent years,china’s wind power has developed rapidly and has become the country with the largest installed wind power capacity in the world.While large-scale wind power grid connection reduces the pressure of energy conservation and environmental protection,the randomness and volatility introduced increase the difficulty of power system operation and dispatch.Assembling energy storage equipment in wind power plant to form wind-storage unit,which can reduce the adverse effect of wind power output uncertainty by controlling the energy storage device to charge and discharge in an orderly manner.It is an effective measure to solve the operation and dispatching problem of power system with large-scale wind power.In the context of power market reform and rapid development of wind power,it is of great significance to promote the further healthy development of wind power by optimizing the use of wind storage resources in dispatching to improve the overall economic benefit and reliability of the system.In this paper,the power system day-ahead dispatching optimization with wind-storage unit is taken as the research topic.On the basis of using the scene set to describe the uncertain factors,the scheduling optimization problem of the day-ahead unit commitment and energy storage participating in the reserve is studied.The main work of the thesis includes:1)As the theoretical and technical basis of the research,the basic concepts of power system dispatching and wind storage are briefly introduced,and the influence of wind power on the power system operation dispatching and application scenarios of energy storage are analyzed.Aiming at the requirement of taking uncertainty into account in the scheduling optimization model,scenario generation and scenario reduction techniques are introduced.Aiming at the solution of the model,piecewise linearization and large M method are introduced.On this basis,the idea of establishingscheduling optimization model based on scene set is expounded.2)This paper established a two-stage scheduling optimization model,aiming at the power system day-ahead scheduling problem with wind-storage units under the power market environment.In the first stage,based on the probabilistic scene set which describes the uncertainty of wind power,considering penalty of the wind curtailment and bidding deviation,taking the maximum expected income of the wind-storage unit as the goal,the day-ahead bid quantity of the unit is optimized.In the second stage,considering the factors such as wind-storage unit force deviation penalty,environmental cost and network constraint,and aiming at the minimum comprehensive operation cost of the system,the day-ahead unit commitment is optimized.In addition,this paper designed a deviation penalty mechanism for day-ahead clearing.The simulation experiment shows that the model has the characteristics of less wind-storage dispatching deviation,lower comprehensive operation cost of the system,and obvious environmental protection benefits.3)Aiming at the problem of how to effectively utilize the adjustable space of energy storage to improve the operation economy and reliability in the power system with wind-storage unit,the paper puts forward the wind-storage operation mode that the energy storage takes part in the reserve while tracking the wind power generation plan.On the basis of describing the uncertainty factors of the system based on the scene set,the expressions of expected energy not supplied,expected wind curtailed and expected wind-storage force deviation are derived,a multi-objective active power and reserve coordination optimization model with minimum system risk,minimum wind-storage force deviation and minimum system operation cost is established.Fuzzy membership function is used to treat the model into a single objective scheduling optimization model to reduce the influence of cost coefficient on scheduling optimization.The simulation analysis shows that the scheduling model can not only improve the economic and reliability of the system operation,but also help to further reduce the deviation of windstorage output,and the optimization of wind-storage operation to take into account the overall safety and economy of the system.