Optimal Solution Characteristics And Application Of Reservoir Mid-long Term Optimal Operation

As clean reproducible energy,hydropower has become a significant choice in the strategic adjustment of energy structure.How to improve water utility efficiency through scientific dispatching and rational planning is a major scientific problem that needs to be solved urgently.Based on the results of mid-long term power generation optimal dispatching,this dissertation has studied on the optimal decision characteristics of adjacent states at same stage and the optimal solution characteristics of the whole process systematically.Then the improved dynamic programming based on optimal decision characteristics(ODC-DP)and the algorithm based on optimal solution characteristics(OSCA)have been proposed and testified.Combined with the characteristics of cascade reservoirs,these improved algorithms have been applied to cascade reservoirs,whose practicability has been testified by case study.The dissertation comprises the following parts:Firstly,with the focus on how to choose optimal decision in different typical reservoirs,this paper analyzes the characteristics of adjacent states’ optimal decision at the same stage,and studies the influence of different factors on the difference between adjacent states’ optimal decision,then demonstrates the correlation between optimal decisions of adjacent states by deducing the formula of the difference between outputs which are transferred to the same final state at single-stage.An improved dynamic programming based on optimal decision characteristics(ODC-DP)is proposed.Taking Tianyi Reservoir as an example,it shows that ODC-DP can greatly improve the computational efficiency without reducing the calculation accuracy,which provides an efficient solution for optimal power generation operation.Secondly,different constraints on mid-long term optimal operation has been discussed fundamentally based on the physical mechanism of objective function.By analyzing the optimal results of hydropower generation operation,the numerical optimal solution of the whole process,as well as the operation property of optimal output,water level and the influence range of the initial and final stages are studied.The concept of breakpoints and truncation are proposed,and the basic law of optimal solution is sorted out.An algorithm based on optimal solution characteristics(OSCA)have been developed.In the case study,the results demonstrate that OSCA can reduce the computational complexity tremendously,which expand a new idea for optimal power generation operation.Thirdly,combined with the characteristics of cascade reservoirs,these improved algorithms have been applied to cascade reservoirs.An improved dynamic programming algorithm that suitable for cascade hydropower generation operation is proposed.Based on the principle of POA,the OSCA has been expanded to a series of OSC-POA for cascade reservoir optimization.Qinshan-Zhouning cascade reservoir is selected as a case study.With the comparison of POA,the rationality,reliability and efficiency of the improved algorithm are verified,which expands the solution to the optimal operation of cascade reservoirs.