Study On Power Generation Plan Of Regional Hydropower Stations In Response To Peak Shaving Requirement

As an easy-to-adjust,low-cost and sustainable energy source,the optimization and scheduling of hydropower can provide theoretical guidance and scientific basis for the efficient utilization of hydropower resources,balance of power supply and demand,and maintenance of safe and stable operation of power systems.Under the trend of the rapid development of water conservancy and electric power construction and the gradual formation of regional grid interconnection patterns,how to fully tap the combined benefits of regional hydropower stations for combined power generation and peak shaving has become a difficult problem in the field of short-term hydropower optimization.In order to improve the dispatching efficiency of hydropower stations and relieve the peak load pressure,this paper takes the hydropower stations in Central China region of the State Grid as the research object,and is carried out around the regional power station group's joint power generation plan in response to peak shaving demand.The main research works and results include:(1)A load distribution method based on the full dynamic characteristic surface of the hydropower station is studied.The complex constraints in the load distribution process are deeply analyzed and a method for constructing the full power characteristic surface of power station with Bi-cubic B-spline is proposed,ensuring the accuracy of the solution while improving the efficiency of the solution.Furthermore,according to the engineering practice of the Geheyan Hydropower Station,the concept of virtual power station is proposed to solve the output restriction problem caused by the way that the unit feeding into power grid,which provides a new method and technical support for the short-term hydropower generation dispatching.(2)From the point of view of the hydropower station unit,the possibility of reserving the adjustable interval for the plant is explored through the better load distribution set by the dynamic programming,and the decision space of the load distribution in the plant is expanded.At the same time,focusing on the peak load demand of power grid,the optimal dispatching model of cascade hydropower stations is established based on minimizing the residual mean square deviation of the power grid.The outer layer determines the output process of the power station by the peak load target,and the inner layer nested the best load distribution set to solve the reserved adjustable interval.And a heuristic load shedding method is put forward for hydropower stations generation plan in response to peak load demand.Taking the Qingjiang cascade hydropower station group as the research object,the results show that the proposed method can effectively reduce the number of crossing vibration area in the actual operation,enhancing the stability of the unit and the applicability of the daily planning.(3)Focusing on the problem of insufficient utilization of water energy resources by inter provincial barriers,the joint optimal dispatching of hydropower stations without cross network transmission tasks is studied.Firstly,single grid peak shaving problem is solved by adaptive differential evolution algorithm and dynamic boundary generation strategy.On this basis,the research on joint peak day planning of regional power grid is developed and the strategy of regional network allocation is put forward.Taking the central China region "Hubei power grid-Qingjiang cascade" and "Hunan power grid-Yuanshui cascade" as example,the results show that the proposed method can give full play to the power exchange capacity of the internet contact line,alleviate the peak shaving pressure of the regional power grid and increase the quantity of electric power of the regional hydropower station,and provide some reference for similar problems.