Study On Optimal Configuration Of Energy Storage System Based On Economic Dispatch Of Wind/energy Storage Combined System

The power structure of our country is mainly based on thermal power.With the massive exploitation and utilization of fossil energy,the drawbacks of the traditional energy utilization model are becoming increasingly prominent.It is imperative to vigorously develop clean new energy.As the most mature technology of new energy generation,wind power has been paid extensive attention and widely applied at our country and abroad.However,wind energy has the nature characteristics of intermittence,randomness and fluctuation.The integration of large scale wind power into the power grid brings a lot of adverse effects on the power grid.Moreover,wind power often has the characteristics of anti peak shaving.After connected to the grid,the wind power will increase the difference of equivalent load between peak and valley which is undertaken by thermal power units,so increase the peak regulating pressure of thermal power units.Energy storage system has the ability of quick energy throughput.With the further maturity of energy storage technology,the increase of operating experience and cost reduction,the large-scale application of energy storage system has been gradually started.The combined operation of energy storage and wind power is an effective way to improve the utilization rate of wind power,which can appropriately reduce the adverse impact of randomness and volatility of wind power on the power grid.If we consider wind power and energy storage as a whole and control the whole wind-storage system,the overall control of the wind-storage combined system can reduce the fluctuation of equivalent load borne by the thermal power units.Therefore in this paper we adopt two scheduling strategies for wind-storage combined transmission system,one is based on the minimum fluctuation of the output of wind-storage system,and another is based on combined system track the load curve.In addition,this paper establishes the economic dispatch model of coal-fired power units considering the cost of coal consumption and pollutant emission.Combined with the actual wind power forecast data and load forecast data,we carry out the simulation of the scheduling output of various power units based on these two scheduling strategies.The simulation results show that these two proposed scheduling strategies can effectively reduce the impact of large-scale wind power fluctuation on the thermal power units.At present,the cost of energy storage system is still high.The investment cost of energy storage system is a factor that has to be taken into consideration when combing wind power and energy storage system.In the aspect of energy storage configuration,this paper adopts an optimal allocation method of energy storage system based on comprehensive energy efficiency maximization.In the model,the economic dispatch cost of thermal power units,the cost of abandoning wind,the cost of network loss and the cost of energy storage system are taken into consideration.The system operation is not only to minimize the scheduling cost and the cost of abandoning wind,but also to balance the economy of energy storage investment.An improved particle swarm optimization algorithm is used to solve the optimization model.Finally,the modified IEEE30 node system is used as an example to carry out the simulation analysis.The simulation results show that the proposed scheme is adapted to different types of energy storage systems.And this paper provides a reference for the application of large-scale energy storage system in the power grid.