| In the actual operation of the cascade pumping station system,there are common problems such as low system efficiency and serious energy waste.This paper started from the comparison and selection of optimization model solving methods.Wolf pack algorithm(WPA)was selected to solve optimization modle and improved.Combining the actual operation of the Bulao cascade pumping station system on the Eastern Route of the South-to-North Water Transfer Project,the optimal operation plan of typical working conditions was decided to realize safe,efficient and economical operation of cascade pumping station system.The main content and results of this paper are as follows:(1)Aiming at the problem of slow convergence of WPA,two improved strategies were proposed:using Halton sequence to initialize the population of algorithm,and mixing in simulated annealing algorithm.These two improved strategies were applied to WPA at the same time,and then the hybrid wolf pack algorithm(HWPA)was proposed.Benchmark function was introduced to test the performance of HWPA.The results showed that HWPA is good at dealing with multimodal and high-dimensional complex functions,and has good global convergence and computational robustness.(2)Taking the optimal operation problem of typical pumping station as research object,single factor analysis and Latin hypercube sampling were used to optimize the four main parameters of HWPA:walking step,running step,minimum and maximum of siege step.The optimal combination of parameters was determined to be 0.32、2.31、0.87 and 4.67×105,and then the improved hybrid wolf pack algorithm(IHWPA)was proposed.The example calculation results showed that the optimization effect of IHWPA on the model is higher than HWPA.Compared with the actual operation scheme,the optimized operation scheme decided by IHWPA can reduce the energy consumption per unit flow operation by 1.48%on average(3)In order to meet timeliness requirements of the water transfer plan,a method based on scheme library to solve optimization model was proposed in this paper.Taking the Bulao cascade pumping station system as research object,the decision-making results of this method and the IHWPA algorithm’s double nesting method were compared.The results showed that the difference in energy consumption between two methods for determining optimal operation plan is extremely small,but the calculation time of the former can be reduced by 98.61%on average compared with the latter.It can be seen that the method based on scheme library is more suitable for solving optimization operation problem of cascade pumping station system.(4)The lowest daily electricity cost of cascade pumping station system was regarded as optimization goal,and the daily optimal operation modle based on time-of-use electricity price was established.The method based on scheme library was applied to the decision-making of optimal operation scheme of cascade pumping station system.Taking the Bulao cascade pumping station system as research object,the operation scheme based on constant daily flow and the operation scheme based on optimized time flow were compared.The latter reduced the daily electricity cost by 11.51%on average compared with the former.(5)Taking the typical working conditions of the Bulao cascade pumping station system as an example,the relationship between daily water transfer volume and electricity cost per unit volume of water transfer was determined.With the increased of daily water transfer volume,the electricity cost per unit volume of water transfer first decreased and then increased.When the daily water transfer volume of the project was 7.27×106 m3,the electricity cost per unit volume reached lowest value,which was 0.0254 yuan/m3.Therefore,it was necessary to determine the optimal daily water transfer volume through calculation and analysis when the short-term daily water supply plan needed to be formulated,so as to improve the economic benefits brought by time-of-use electricity price policy. |
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