Research On Multi-objective Optimization Of Cascade Reservoirs

China is relatively short of water resources.According to statistics,the amount of water resources per capita is only 2100 cubic meters,only 28%of the global average.On the other hand,China’s water resources distribution is very uneven,the vast northern areas are generally serious water shortage.With the development of economy and society,people put forward higher requirements for water resources.Therefore,the optimization of dispatching and the use of water resources is a major issue in economic management.The problem of water resources dispatching must take into account the economic operation,environmental protection and people’s life in different regions.As more and more factors are taken into account in this kind of scheduling problem,intelligent optimization algorithm has become the most popular emerging technology means to solve this kind of scheduling problem,and has been studied in depth and more widely used.It is of great significance to construct a scientific and reasonable joint water resource dispatching method for improving the utilization efficiency of water energy resources and giving full play to the advantages of water resources in economic and social development,energy conservation and emission reduction.Based on the present situation as the background,the operation of cascade reservoirs combined with the theory of optimal allocation of water resources,benefit balanced multi-objective optimization method,modeling theory of cascade reservoirs optimization operation is further studied,model and solving method,put forward the research ideas and methods to improve the cascade reservoirs of water resources utilization,provide theoretical support for water of river basin water.The main contents and innovative achievements of this paper are as follows:(1)Construction of multi-objective particle swarm optimization algorithm based on cascade reservoirs.Aiming at the convergence and efficiency problems in multi-objective PSO,this paper improves the inertia weight,achieves a balance between the global search and the local search,and proposes an improved multi-objective PSO,the MQPSO,and verifies it using the universal ZDT and DTLZ series functions.The results show that the MQPSO is significantly different from the comparison algorithms.In addition,ZDT and DTLZ series functions commonly used in the world are used to test the improved algorithm,and the rationality and feasibility of the algorithm are verified from the aspects of stability,convergence effect,calculation speed and solution result.Then take electric power economic dispatch as an example,which further verifies the feasibility of the algorithm.(2)Establish a cascade reservoirs operation model with water supply as the optimal,calculate the joint optimal operation of the reservoirs,and determine the optimal water supply plan of the reservoirs.In order to verify the effectiveness and practicability of the multi-objective optimization algorithm,the reservoirs in Hongruhe basin was simulated according to the actual operation rules,and the proposed MQPSO algorithm was used to solve the problem.Results show that compared with the actual operation rules,the adaptive algorithm,improved operators of the algorithm and improved step by step algorithm of total water supply on the basis of the simulation are improved,shows that in the long-term operation scheduling in different water supply scheme of optimization algorithm on the basis of the simulation scheme has certain improvement,for reservoir optimal operation has opened up a new way of solving the problem.(3)Research on optimal operation of cascade reservoir water quantity and quality.Considering the ecological environmental water demand,water quantity,water quality and other factors of cascade reservoir group,Copula function is used to connect the variable joint cumulative distribution function with the variable marginal cumulative distribution function to establish the water and water quality optimization model.With Hongru River as an example,according to the relevant data of the HongRuHer basin,the Chemical Oxygen Demand(COD)is taken as the pollution indicator for optimization dispatching.With the expected water quality of the six major water quality control sections in the Hongruhe River basin reaches Class as the goal,this paper obtains the water volume and quality joint dispatching scheme for the Hongruhe River basin.The proposed MQPSO algorithm is used to systematically study the water quality,improve the rate of reaching the standard,give full play to the potential efficiency of water resources,and lay a foundation for the improvement of the water environment of the basin.(4)Research on optimal operation of hydropower generation in high and low water period of cascade reservoir group.Aiming at the problem that the application effect of reservoir dispatching map of reservoir group hydropower stations in the region of flow is not good,this chapter proposes a phased dispatching map considering the difference of output in different periods of the year.The method can clearly divide the hydrologic year,high water period and low water period of reservoir group.Preliminary empirical study shows that the proposed scheduling diagram is obviously superior to the conventional scheduling diagram,and can effectively bring into play the benefit space of hongru River basin hydropower station.In this paper,the cascade reservoir group of multi-objective scheduling problem is studied,combined with the proposed MQPSO algorithm,separately to consider quantity of cascade reservoir group of multi-objective optimization scheduling,taking into account the water quality of cascade reservoir group of multi-objective optimization scheduling research and consider the plentiful power generation of cascade reservoir group of multi-objective optimization scheduling are studied,and the model and algorithm were Hongruhe empirical simulation of cascade reservoirs,effectively prove the algorithm and the adaptability and flexibility of the model.It advances the technical level of optimal operation of cascade reservoirs and provides new and effective theory and method for optimal operation in practice.