Research And Development Of Secondary Water Supply Control System

Water is the basis of human survival,how to provide high-quality water supply services and maximize energy saving has been a hot issue.China is a country seriously short of water resources and electric energy,limiting by backward water supply equipment and control technology,the degree of automation of urban secondary water supply system is low for a long time,which can not guarantee the normal needs of residents in their life and production,and the waste of electric energy in water supply equipment is serious.Therefore,how to effectively use automation technology to design high-performance,high reliability,low energy consumption water supply system is imminent.This paper relies on the "13th five year plan" water conservancy project "research and development and demonstration of secondary water supply equipment based on fine control",with the help of the experimental platform of Shanghai WPG intelligent water company,according to the basic characteristics of water supply system and permanent magnet synchronous motor,a new nonlinear secondary water supply system model is established,analyzing the energy saving principle and technological process of the secondary water supply system.By studying the principle and structure of the system,a multi pump constant pressure secondary water supply system is designed with the programmable industrial controller independently developed by Shanghai WPG intelligent water company as the control core.In terms of control strategy,the urban secondary water supply system has the characteristics of long time delay,nonlinearity and many disturbances,conventional PID control is difficult to achieve ideal control effect.Therefore,this paper designs a nonlinear adaptive backstepping control strategy,which fully adapts to the nonlinearity of the secondary water supply system.At the same time,RBF neural network is used to approximate the unknown nonlinear parameters,throughing estimating the maximum value of the neural network parameters rather than the parameters themselves,the parameters of the neural network estimated online are greatly reduced,which can significantly reduce the online learning time of neural network and overcome the problem of learning parameter explosion caused by online approximation of neural network.In order to reduce the complexity of control design process and avoid the "computational expansion" problem in backstepping design method,dynamic surface control technology is introduced to simplify the structure of the controller.The traditional PID control strategy and the backstepping control strategy are simulated by computer and the simulation results show that the control quality of the secondary water supply system based on this strategy has been greatly improved.On the basis of analysis and design,the software and hardware of the secondary water supply system are designed,and the electrical schematic diagram of each part of the system and the connection diagram of the control cabinet are drawn.In the aspect of control program design,the structured programming method is adopted,each function of the system is compiled into corresponding subprogram block,which is called by the main program according to the conditions.Finally,the secondary water supply system designed in this paper is evaluated by experiments.The results show that the system has good control effect,high reliability and obvious energy-saving effect,which can meet the needs of urban secondary water supply.