Research Of Unit Load Model And Its Application Of Hydropower Station

As the most mature technology,the most economical development,the most flexible scheduling of clean low-carbon renewable energy without greenhouse gas emissions,hydropower plays a significant role in energy development and electric power industry.Reservoir operation is an important part of comprehensive development and efficient utilization of water resources.Short-term optimal operation usually includes the economic operation of inner-plants units and belongs to a complex multi-dimensional,nonlinear,discrete and large-scale space-time decision-making optimization problems,the curse of dimensionality has always been a major bottleneck restricting the short-term optimal operation of hydropower stations.The conventional Iterative Algorithm of generating discharge has some problems,such as large computational complexity,slow convergence and low computational efficiency.Based on the analysis of actual load characteristics of hydropower station,this paper proposes the Unit Load Model and Unit Generating Discharge Recursive Algorithm starting from unit,also gives the concrete derivation process of the formulas of unit discharge difference between the adjacent time and the total water consumption.Finally,the Unit Generating Discharge Recursive Algorithm is compared with the Iterative Algorithm both applied to case study.The main contents of this paper include the following aspects:(1)The Research of Unit Load Model.Aiming at the problems existing in the short-term optimal operation of hydropower stations,such as unclear temporal and spatial variation of daily load characteristics,curse of dimensionality and so on,this part mainly develops the research on the spatial-temporal evolution mechanism of hydropower daily load,then proposes the concept of Unit Load Model by analyzing actual load characteristics of hydropower station,which uses the mathematical language to describe the structural characteristics of unit single start fixed load operation process,and introduces the parameters,structure and constraints of this model.The analysis from the perspective of unit ? hydropower station is that building the daily load process of unit and hydropower station with Unit Load Model,at the same time,discussing the number of times of units travers cavitation vibration zone under different conditions.Under the premise of given environment control variables,by optimizing the control of a few Unit Load Model variable parameters,the actual structure of the system can be indirectly optimized,which greatly reduces the number of decision variables in the optimization mathematical model and avoid the problem that the short-term optimal operation mathematical model nests the load optimization model of inner-plants units.(2)The Research of Unit Generating Discharge Recursive Algorithm.In view of the problems that large computational complexity,slow convergence and low computational efficiency of Iterative Algorithm,this part proposes a new method,Unit Generating Discharge Recursive Algorithm,also gives the concrete derivation process of the formulas of unit discharge difference between the adjacent time and the total water consumption,and the situation of generating discharge difference solution under different conditions is discussed.Furthermore,analyzing the formulas of unit discharge difference under different combination among one unit and many units,stable and unstable upper stream and output or repeatedly start-stop.Unit Generating Discharge Recursive Algorithm from a certain extent can avoid the iterative calculation process of generating discharge by time,and has higher computational efficiency.(3)The Research of short-term optimal operation of hydropower station based on Unit Load Model and Unit Generating Discharge Recursive Algorithm.According to the historical daily load process data of hydropower station,the typical daily load diagram is constructed and optimized.This part builds the minimum water consumption model of hydropower station based on Unit Load Model,and proposes solving method.At last,the results are compared with Iterative Algorithm in case study.Taking the Mianhuatan Hydropower Station in Fujian Province as an example,and the application results show that Unit Generating Discharge Recursive Algorithm gets the minimum daily water consumption an increase of about 0.1071‰ compared with Iterative Algorithm,and the daily water consumption rate increased by about 0.1108%o(the difference is 0.0037‰,and this error is related to the effective number of bits of calculated results),and the computation time is reduced by about 8%,which verifies the practicability and effectiveness of Unit Generating Discharge Recursive Algorithm.Finally,it summarizes the research results of the whole paper,also prospects the shortcomings and something needed for further research.