Research On The Coordinated Control Of High Efficiency Motor-mump System

The motor-pump system occupies the main position in the fields of industry and agriculture,and the electricity consumption accounts for 20%of the country total electricityannually.Ifimproving the efficiency and reduce the energy consumed of the motor-pump system,it will be of great significance for the development of green energy economy.The key technology is to make the motor-pump system run in the high efficiency range when the system meets the demand.At present,the frequency control is usually adopted to improve the system efficiency,but this method will make the centrifugal pump departure the design point to work.In this paper,the traditional valve control and speed control combined to control the motor-pump system.The effect of high efficiency and energy saving of coordinated control and the reliability of the system are emphatically studied.The main research work of this paper as follows:1)The vector control system of three-phase induction motor and the physical model of centrifugal pump are established respectively.And the motor-pump system model is established.Meanwhile,the correctness of the model is verified by simulation.2)The external characteristics of the centrifugal pump are analyzed.At the same time,with high efficiency system as the goal to carry out the valve control and speed control for motor-pump system.Then the opening range of the valve and speed range are obtained when the centrifugal pump runs in the high efficiency area under the two control modes.Finally,the BP neural network is used to predict the adjustment range of the valve opening and speed when the coordinated control mode work in the high efficient region of the centrifugal pump.3)Aiming at the poor dynamic performance of conventional coordinated control,on the one hand,thefuzzy adaptive control is used to optimize PID parameters in valve control.On the other hand,the vector control flux observer is optimized to achieve a better dynamic performance optimization control in speed control.On this basis,the division coordinated control strategy is adopted to improve the performance of the system in different requirement occasion with high efficiency.Based on the above analysis,the coordinated control method adopted in this paper is superior to valve control and speed control in the aspect of energy efficiency,and its reliability is also stable,which can better approach the operation of the system operation point.Andthe work of this thesis is supported by the national science and technologysupport Project of China "The research and application of large fluid mechanical energy-saving technology(2013BAF01B02)" and "The National Science Research Key Program of Anhui Provincial Education Department(KJ2016 A021)".