Research On Economic Dispatch For Power System Considering The Dynamic Dependence Of High Dimensional Wind Farms

With the rapid development of economy and society,the country is paying more and more attention to ecological and environmental issues.In view of the large consumption and high carbon emissions of fossil energy,a series of policies have been put forward to promote the development of renewable and new energy power generation.Wind power generation has been widely used for its advantages of zero emission and short infrastructure cycle,but its intermittent,random and volatile characteristics also bring new challenges to the security and economic operation of power grid.In this thesis,the dynamic dependence characteristics of high-dimensional wind farms output is modeled,and the economic dispatch of power system considering the dynamic dependence of high-dimensional wind farms is studied.With the large-scale grid integration of wind power,there is the strong correlation between the output of several wind farms due to the similarity of their geographical location and weather.In this thesis,the output of a single wind farm and several wind farms are analyzed,and the dynamic dependence of the high-dimensional wind farms' output is modeled by using pair-copula function.The non-normal characteristics of the output of a single wind farm and the non-linear,asymmetric and up-down-tail dependence characteristics of the multiple wind farms' output are described purely.Considering the diversity of new energy sources in the same region,this thesis establishes a dynamic dependency model considering the output of multi-wind farms and photovoltaic power plants;to deal with the stochastic characteristics of wind and photovoltaic grid-connected,a dynamic economic dispatch model of power system is established based on scenario method with the objective of minimizing the system coal consumption and the re-dispatching cost.To overcome the shortcomings of the traditional particle swarm optimization(PSO)algorithm,such as premature maturity and easy to fall into local extreme points,an improved particle swarm optimization(IPSO)algorithm is proposed to solve the economic dispatching model.Finally,an improved IEEE 39-bus system is taken as an example to verify the effectiveness of the proposed model and algorithm.On this basis,a high-dimensional dynamic pair-copula model with multi-wind farms output is established based on the copula theory;a dynamic economic dispatching model is established based on scenario method with the objective of minimizing the system coal consumption and the emission cost of polluted gases;in view of the low solving efficiency of the dynamic economic dispatch model considering the multiple wind farms connected to grid,this thesis presents a dynamic economic dispatch model with high dimensional scenarios decoupling based on the multidisciplinary collaborative optimization(MCO)algorithm,and a dynamic optimal relaxation optimization model is established to obtain the optimal relaxation variables for the system level optimization model,which realizes the reduction of the dimension of the original problem and effectively improves the efficiency of the solution.The effectiveness and practicability of the proposed model and algorithm are verified by the IEEE 118-bus system and an actual provincial power grid.