The Research On Unit Commitment And Dispatch Strategy Of Power System With High Wind Power Penetration

With the further implementation and deepening of the target of “Carbon Emission Peak” and “Carbon Neutrality”,the proportion of renewable energy such as wind power in the power system is increasing fastly,but its uncertainty and nonlinearly characteristics also introduce new challenges such as the security operation and reliable consumption of the renewable energy in the system.Therefore,it is urgent to study the flexible operation and risk dispatch strategy in the power system with high penetration wind power.Relying on the security,controllability,flexibility and intelligence of the new power system,combined with the flexible and controllable dynamic line rating(DLR)technology,and comprehensively considering the potential risks of wind power uncertainty and the false data injection attack,guide the power dispatching department to determine a scientific and reasonable day-ahead unit commitment plan and an intra-day real-time dispatch strategy to achieve reliable consumption of the renewable energies.In the view of demands and challenges,this paper focuses on the security and optimal operation of the power system under wind power uncertainty,and studies corresponding to the day-ahead unit commitment model and the intra-day dispatch strategy.The emphasis and achievement of the paper mainly manifests in the following aspects:(1)A chance-constrained unit commitment model considering the uncertainties of DLR and wind power is proposed to improve the problem of low wind power consumption in the power system caused by wind power uncertainty.Firstly,for reducing the prediction error of DLR,a combined DLR forecast algori thm based on the entropy evaluation method is established by using the Elman neural network and multivariate adaptive regression splines model.Secondly,the chance-constrained constraints about the uncertainties of DLR and wind power are constructed,and a chance-constrained unit commitment model considering DLR and wind power is formulated.Finally,the case study based on the actual system proves that the proposed model can optimize the day-ahead unit commitment plan and improve the wind power absorption capacity of the power system significantly.This model can also reasonably control the risks caused by DLR and wind power uncertainty,which has better robustness.(2)Aiming at the system intra-interval security risks caused by the nonlinear characteristic of wind power,an intra-interval security preventive security-constraint unit commitment(IPUC)model is proposed to ensure the security of the power system during the dispatch interval.Besides,a Benders-like decomposition algorithm is presented,which can solve the IPUC tri-level model quickly by adding a few Benders-like cuts.And the day-ahead unit commitment and the corresponding intra-day optimal dispatch strategy based on the IPUC model can eliminate the risk of intra-interval power imbalance even in the worst-case.The actual system simulation results indicate that the proposed IPUC model can enhance the ability of the power system to prevent the intra-interval risks when the wind power penetration is high.(3)In order to effectively intra-day optimal dispatching and mitigate the overloaded risk caused by the uncertainties of DLR and wind power,based on the day-ahead unit commitment model considering DLR,an intra-day tri-level preventive dispatch model considering the uncertainties of DLR and wind power is proposed.Firstly,the Monte Carlo method is used to generate a large number of DLR scenarios,combined with the Density-based spatial clustering of application with noise(DBSCAN)algorithm to eliminate extreme DLR scenarios and extract typic al DLR scenarios,thereby reducing the conservativeness of the intra-day economic dispatch strategy.Secondly,a tri-level intra-day preventive dispatch model is constructed considering the uncertainties of DLR and wind power.The upper-level is to determine a secure preventive dispatch strategy,the middle-level is to identify the worst scenarios of wind power,and the lower-level is to capture the actual line power flow.In addition,a fast solution method by identifying the high-risk lines is presented to solve the proposed tri-level optimization model fastly and improve the applicability of the proposed model in large-scale systems.Finally,the actual system simulations prove that the proposed intra-day preventive dispatch model can maximize the economic benefits brought by DLR technology and promote the consumption of renewable energy such as wind power under the condition of ensuring system security.(4)Aiming at the risk of the false data injection attack against load with wind power(FDIA-DW)introduced by cyber-physical characteristics in the new power system,an intra-day tri-level secure dispatch model for preventing FDIA-DW is proposed.The false data injection attack against load with wind power could mislead the system to make wrong operation decisions by obtaining and tampering with the wind power output at the source end and the smart meter data at the load in the power system.Therefore,the principle of FDAI-DW induce line overloaded is firstly studied,and a risk evaluation model of the FDIA-DW is established.Then,an intra-day tri-level secure dispatch model is proposed to prevent the risk of FDIA-DW,and a corresponding Benders-like decomposition algorithm is provided to solve the above tri-level optimization problem.The simulation results show that the intra-day secure dispatch model can determine the corresponding preventive dispatch strategy based on identifying the worst-case of FDIA-DW,the proposed model ensures the system can be converted to a security and economic operation state when it is attacked by the FDIA-DW.