Research On Coordinated Optimal Dispatch Of Wind-nuclear Power Considering Peak Load Shaving Of Nuclear Power Plant

With the continuous increase of peak-valley load difference in coastal areas of China,and the construction and development of onshore wind power,offshore wind power and nuclear power projects,the peak load regulation pressure of coastal power grids will be seriously aggravated.Especially because of the inverse peak regulation characteristic of wind power,it will force conventional units to start and stop frequently and severe wind curtailment.Modern nuclear power units have the ability of daily load following,and new generation nuclear power units such as EPR and AP1000 with better operation performance have been built and connected to power grid in China.Considering nuclear power participating in daily peak shaving and coordinating with wind power and other power sources,it is of great significance to meet peak shaving demand of power grid,reduce wind abandonment and improve operation safety and economy.Based on the project of National Natural Science Foundation of China and the analysis of flexibility,safety and economy of daily peak shaving for nuclear power units,this paper studies the modeling of daily load following for nuclear power units and the coordinated dispatch with wind power and other power sources.The main research contents and conclusions are as follows:(1)The flexibility,safety and economy of daily load following for nuclear power units are analyzed.Based on the design requirements and operation experience of load following for nuclear power plants,the performance of uniform and step power adjustment is verified by simulation.the impact of daily peak shaving on the safety of nuclear power plants and systems is analyzed,and the impact on the economy of nuclear power plant and system is analyzed based on the levelized cost of electricity and peak shaving cost,respectively.(2)A daily load following operation model of nuclear power unit suitable for power system dispatching optimization is established.All peak-shaving nuclear power units are equivalent to one unit,and daily peak-shaving coordination is achieved by arranging peak-shaving in turn.Considering the fuel cost,safety cost and special operation constraints,a daily load following operation model of nuclear power units suitable for power system dispatching is established,and a method of subdividing the depth of peak-shaving is proposed to linearize the operation constraints of nuclear power.The effectiveness of the proposed model and method is verified by simulation.(3)A wind-nuclear power coordinated optimal dispatching model considering peakshaving of nuclear power is established.Based on the characteristics of wind power and the peak load shaving of nuclear power,its matching characteristics is analyzed.According to the principle of economic dispatching,considering wind curtailment cost,nuclear power peak shaving cost and special operation constraints,a coordinated dispatching model of wind-nuclear power is established.A numerical example validates the matching characteristics and the economics of coordinated dispatching of wind-nuclear power.Furthermore,the influence of wind curtailment cost coefficient and wind power reserve coefficient on dispatch is analyzed.