Optimal Operation Modeling Study Of Urban Water Supply System Based On BP Neural Network And Genetic Algorithm

Along with the improvement of social productivity, the extension of city size and enhance of people's consciousness to energy saving and water saving, standards of water supply system are becoming higher, so study on optimal and safe operation of water distribution system(WDS) is facing to new challenges and development.Interrelated theories, methods of model building and some equations' solution are studied firstly in more detail in this paper, then some problems of WDS' optimal operation at present are summarized according to pioneer studiers. Taking our county's practice of water supply system into account, this study take water supply system of Nanjing city as subject, and build adaptive models of hourly water consumption forecasting, water distribution network and optimal operation respectively. This study will offer a feasible method for optimal and safe operation that is hopeful for maximizing water supply companies' economic and social benefits. Furthermore, this paper can also provide reference for other study and guidance for practice in this field.The mainly work of this study are as following aspects:1. Synthetically analyze and compare the methods and models of water consumption forecasting firstly, to explore the merits and setbacks of them. For regression model and time series model have difficulties in equations formulation, developing them based on BP neural network are studied. Because of these two kinds of model's inherent setbacks in prediction, a theory of optimizing combinatorial coefficients is introduced and a combined model based on them is developed. Furthermore, an example of forecasting hourly water consumption of Nanjing city is used to confirm the combined model's practicability and feasibility.2. Summarize the common ways of developing equivalent model of water distribution network home and abroad, especially analysis the peculiarities of microcosmic equivalent model and macroscopic equivalent model. Based on our county's practice of water supply system and characteristics of Nanjing's, a time-division macroscopic equivalent model on BP network is built, and it's rationality and feasibility is also confirmed.3. Based on given cases, analyze the peculiarities of the direct optimal operation model and two-stage optimal operation model of water supply systems. Since most of water supply systems in medium and large-scale cities of our county are complex with their pump stations mixed with fixed and variable speed pumps, a two-stage optimal operation model with equations formulation is established based on water supply system of Nanjing city.