Research On Complementary Short-term Dispatching Of Cascade Hydro-solar System In Watershed

In order to achieve the goal of " Carbon Peaking and Carbon Neutrality Goals",new energy such as wind power and solar energy has developed rapidly in recent years.Large-scale new energy grid connection has made the safe and stable operation of power grid and the difficulty of new energy consumption increasingly serious.Relying on China’s large-scale river basin cascade power stations,complementing with the new energy power stations around the river basin,relying on the flexible regulation capacity of hydropower,stabilizing the fluctuation of wind and solar output,and forming a stable River Basin Cascade clean energy corridor complementary dispatching mode is a practical technical solution for Carbon Peaking and Carbon Neutrality Goals.However,on the premise of considering the complex power grid structure,regulation and management relationship,how to tap the reserve of hydropower and quantify the reserve demand of new energy,respond to the load requirements of power grid,and then optimize the short-term power generation plan is an urgent problem to be solved for multi energy complementary short-term dispatching.Therefore,this paper takes the photovoltaic power stations in Beipan River and southwest Guizhou Province as the research object.Aiming at the problem of short-term complementary dispatching in watershed hydrosolar zoning,this paper research the reserve supply-demand relationship and multi grid load response demand in zoning under nested section.The main research contents are as follows:(1)A hydro-solar system short-term scheduling method based on nested cross-section zoning transmission constraints.Facing the problem of hydro-solar system occupying the transmission channel,the traditional short-term scheduling model only considers the transmission capacity limit,and rarely considers the spatio-temporal coupling constraints of complex grid structure and photovoltaic output fluctuation.Therefore,this section carries out hydro-solar zoning based on nested sections,and quantifies the reserve supply of hydropower and the reserve demand of photovoltaic prediction deviation in each zoning.On this basis,a short-term complementary scheduling model of hydro-solar zoning reserve aiming at peak shaving is established,and a verification method of photovoltaic power scene series and power abandonment generated is used.In this paper,the output of photovoltaic power station is analyzed and compared with that of conventional photovoltaic power station,and the output of cascade power generation channel is adjusted reasonably to ensure the complementary effect of solar station under the limitation of peak power supply and regulation,so as to reduce the peak power supply efficiency of photovoltaic power station.(2)A short-term scheduling method for load response of multi grid in hydro-solar zoning based on chance constrained programming.Facing the complicated regulation and management relationship of cascade hydropower stations,which belong to different dispatching institutions,and need to respond to the load change demand of different power grids and the impact of photovoltaic randomness on the out of limit of external transmission channels,a multi grid short-term peak shaving model based on the out of limit possibility opportunity constraint of external transmission section constraint is proposed.The fuzzy membership function method and improved K-means clustering are used as the peak to valley time division method of the load curve of the outgoing power grid,and the typical outgoing power transmission curve with load characteristics is generated combined with the utilization coefficient of the transmission channel.On this basis,the photovoltaic uncertainty is transformed into section chance constraints,and then transformed into deterministic constraints by sampling principle.The application example shows that the solution result of the proposed model fully reflects the relationship between the demand response of multi grid peak shaving and the opportunity constraint of zoning section,and can fully consider the influence of photovoltaic randomness,make use of hydropower to make way for photovoltaic,and realize the goal of multi grid peak shaving under hydro-solar complementarity.At the same time,the actual scheduling can also provide decision-making reference for dispatchers by reasonably adjusting the target weight and confidence level in the model.