Modelling And Algorithm Of Interval Planning And Economic Dispatch Of Energy Storage For Power Grid With Wind Power System

For the purpose of solving the problems of energy crisis and air pollution,the world is carrying out a green industrial revolution vigorously focusing on the development of clean and renewable energy such as wind power.However,the intermittence and randomness of wind power make it for power grid difficult to assess the power supply reliability and control the dispatching operation.Energy storage system(ESS),as a kind of adjustable resource for charging and discharging,has the characteristics of flexible throughput and fast energy response speed.Connecting it to the power grid can improve the operation influence of wind power grid-connected system.Therefore,this paper focuses on the energy storage planning and economic dispatch of power grid with wind power.The content of the paper mainly includes:1)Aiming at the problem that the uncertainty of wind power and load affect the power supply reliability of the power grid,an interval reliability evaluation method that takes into consideration wind power and energy storage devices is proposed.Firstly,the states of wind turbines and generators are generated based on sequential Monte Carlo method,and then interval reliability assessment model of the grid is established,and then the interval reliability evaluation model is established.The uncertain optimization model is transformed into the deterministic optimization model under two extreme circumstances by using the method of interval possibility degree.The maximum non-load shedding probability of the power supply side considering the interval output of wind power in the grid to meet the interval demand of load is sought by optimizing the output of energy storage and the units,that is,the upper boundary of the load shedding is the smallest.Finally,the interval reliability index is calculated,which provides a basis for establishing interval optimal allocation model of energy storage.2)To improve reliability of power supplying of the grid,an interval planning method considering energy storage is proposed.Based on the uncertainty of wind power and load,the coupling relationship between the early planning and the later operation of the energy storage device is fully considered,and the sum of the annual comprehensive cost with energy storage and unit and annual outage loss cost is minimized as the optimization objective to establish the energy storage interval planning model.To require the optimal energy storage planning result,on the one hand,by looking for the maximum non-load shedding probability for the power supply side to meet the system load interval demand,the interval planning model is transformed into a deterministic planning model for the upper limit of the load shedding amount in the worst scenario.On the other hand,in order to reinforce global optimal search capability of the conventional particle swarm algorithm,local search is added to the algorithm and crossover operations are introduced to solve and calculate the energy storage interval planning model.3)In order to solve the impact of wind power integration on the economic operation and safe operation of power system dispatching,considering the installation of energy storage and SVC in the system,and combining the operation characteristics of the two,the active power economic dispatching and reactive power optimization are combined,and a multi-objective collaborative optimization method considering energy storage and SVC is proposed.In the process of collaborative optimization,through the collaborative iteration of active-reactive power dispatching,the equilibrium optimal results which takes into consideration both the economy and the security of the grid is acquired.Finally,the proposed algorithm is compared with the Pareto front solution set of multi-objective decision-making obtained by the ideal point method with weight coefficient,and the solution verifies the proposed algorithm can avoid the subjective factors in settling the multi-objective weight factor.In summary,in view of the uncertainty and volatility of wind power and load of the grid,an interval reliability evaluation method,an energy storage interval planning model and a collaborative optimization dispatching method considering the simultaneous access of SVC and energy storage are proposed.The feasibility and availability of the method and model are tested by examples,which provides technical support for the reliable operation of the grid,energy storage planning and dispatching decision.