Research On Security And Economic Dispatching Of New Power System Considering Reserve Risk

In the context of profound adjustment and changes in the world energy pattern and market supply and demand relationship,the uncertainty of both supply and demand of the electric power system has been significantly enhanced.Construction of new electric power system with new energy as the main body has become the way to ensure our country’s energy security,promote the upgrading of the energy industry,and realize the transformation of energy system to low-carbon and clean.However,the new power system will face more random disturbance due to its high proportion of internal new energy uncertainty characteristics,and the operation risks such as supply and demand mismatch will become more prominent.In this context,the allocation of spinning standby resources is one of the important means to ensure the safe and stable operation of the power grid.How to efficiently utilize the standby resources and other flexible resources in the system to ensure the economic benefits of the new power system while reducing its potential operation risks has become the research focus in the field of security and economic dispatching of the new power system.First of all,this study introduces the basic concept and theoretical framework of stochastic power flow in power system,which lays a theoretical foundation for the construction of reserve risk index in the following chapters and the rational allocation of reserve resources at the source side and controllable resources at the network side.Secondly,in order to fully tap the reserve potential of the source side,this thesis proposes a reserve risk assessment index that takes into account the power flow over the limit,so as to accurately quantify the excess risk caused by insufficient reserve.At the same time,in order to efficiently utilize various flexible resources in the power system to reduce the risk of system overrunning,this thesis comprehensively considers the reserve capacity of the source side and controllable components of the grid side,takes the minimum system operation cost and the minimum index value of the system operation overrunning risk as the optimization objective,and constructs a new safety and economic dispatching model of the power system that takes reserve risk into account.In this model,the reserve resources at source side and network side are considered comprehensively in the scheduling process,and the power over-limit risk is reduced by the reasonable allocation of spinning reserve,and the network segment controllable element is used to reduce the voltage over-limit risk,so as to effectively deal with the over-limit risk brought by the power flow fluctuation to the new power system.Thirdly,in view of the non-convex nonlinear and multi-objective coupling characteristics of the constructed new power system security and economic scheduling considering reserve risks,this study draws on the efficient random walk foraging behavior of Marine predators,integrates two random walk mechanisms,Brownian motion and Levy flight,and integrates them with the efficient differential evolutionary algorithm.A novel Brownian-Levy multiple objective differential evolution algorithm is proposed.In the process of optimization,the algorithm can repeatedly and efficiently adjust the search area of evolutionary individuals,so that the population always maintains diversity in the process of evolution,and the global search and local search capabilities are well balanced.Finally,the improved IEEE-30 node system was taken as an example for simulation calculation.Analysis of the simulation results showed that the reserve risk index proposed in this thesis could accurately quantify the over-limit risk caused by insufficient reserve,and the optimized reserve scheme based on this index could adaptively configure the spinning reserve capacity with the size of the system over-limit risk.In addition,The source network cooperative security economic dispatching model proposed in this thesis can improve the voltage level and effectively reduce the system over-limit risk.Compared with the traditional dispatching model,it is more conducive to ensure the safe and stable operation of the system,which makes the proposed dispatching scheme have better adaptability in practical engineering.Meanwhile,by comparing and analyzing the Brownian-Levy multi-objective differential evolution algorithm and the commonly used multi-objective optimization algorithm,it is verified that the proposed algorithm has better performance in terms of solving quality.The idea of uncertainty modeling and multi-objective optimization algorithm considering stochastic power flow proposed in this study can be further extended to the optimization calculation of source-grid-load-storage coordination.