Research On Optimal Scheduling Of Hydropower Stations In Regional Power Grid

The optimal scheduling of hydropower stations in regional power grid has the characteristics of multi-dimension of time and space,multi-objective and different scheduling subject.And with the constraints of hydrological cycle,grid load and water supply,the optimal operation of hydropower stations is a large-scale,multi constraint,high-dimension,nonlinear optimal problem.As the rapid development of hydropower energy construction in China and the national power grid pattern,the relationship between hydropower and gird is becoming more and more complex.Under this background,carrying out the research on the short and long-term optimal scheduling of hydropower stations in regional power grid,coordinating the relationship of scheduling objectives like power generation and peaking,balancing the needs of multiple power supply areas,fully tap the comprehensive benefits of the collaborative optimization of hydropower station in the region,is a hot and difficult topic in the field of optimal scheduling of hydropower station.For this reason,this paper focuses on the research of coordination optimal scheduling problem of hydropower stations in regional power grid:(1)An efficient algorithm for solving long term cooperative optimal scheduling of cascade hydropower stations.This paper explores the key factors that influence the global convergence behavior of POA and presents a variable period progressive optimality algorithm(VPPOA).This new algorithm adopts a progressive differential strategy and a variable period strategy to replace respectively the approach used for solution of two-period optimal problems and the two-period optimal strategy in traditional POA,so that it can overcome the premature convergence problem caused by poor initial solution.Simulation results of optimal dispatch for the lower Jinsha River show that the proposed algorithm effectively overcomes the local convergence of the original algorithm,and the optimal result is more stable.Thus,VPPOA is an efficient algorithm for solving optimal scheduling problem of cascade hydropower stations.(2)Furtherly,to studying the problem of peak load in the midterm optimal scheduling of cascade hydropower stations,this paper sets up a midterm maximum peak load regulation model that the daily power scheduling is embedded in the midterm optimal scheduling.In this paper,the outer model is solved by the VPPOA algorithm,and the inner model adopts successive load shedding algorithm on load distribution.Case study shows that the proposed midterm maximum peak load regulation model can balance the demand of power balance in different dispatching period,and the scheduling result has better practical application value comparing to the maximum power generation model.(3)Research on the short term coordinated optimal dispatch of regional power grid.The informations are asymmetry between the multistage generation dispatching mechanism which is composed of the central China power grid,the provincial power grid,power dispatching agencies in basin center and hydropower plant.It is difficult to unify the optimal dispatching of power grid which caused by the different targets.To solve the problem,this paper put forward a "bottom-up reporting,top-down publishing" multi-level cooperative optimal scheduling method,and propose a daily planning method of multi objective to response peak shaving demand,a optimal allocation way which is based on the combination of interval forward load shedding method and interval inverse load shedding method.After verification,the proposed methods can greatly exploit the peak potential of hydropower stations in regional power grid,balance the different needs to multiple areas,and achieve multi-level cooperative scheduling finally.