Design And Research On Electric Drive Compressor Unit Control System

In recent years,with governmental efforts to develop clean energy and optimize energy structure,the demand for efficient and clean fossil energy represented by natural gas is increasing.However,domestic natural gas resources are mainly concentrated in the underdeveloped western regions.In order to transport the natural gas from the western regions to the central and eastern regions rapidly,the natural gas in the pipeline must be pressurized.Compressor,which provides power for natural gas transportation and acts as the heart of pipeline transportation,is the most important equipment in the compressor station.Therefore,it is of great theoretical significance and practical value to design and study the control system of electric drive compressor.This paper takes long-distance natural gas transportation system as the background and electric drive compressor unit as the research object.On the basis of sufficient field investigation and theoretical study,the technological process of the entire compressor station is analyzed,and the composition of the compressor station and the function of the main equipment are described.According to the working principle and performance curve of centrifugal compressor,the mathematical model of centrifugal compressor speed and outlet pressure is established.Through comparing the advantages and disadvantages of various adjustment modes of centrifugal compressor,the overall control frame of cascade adjustment is determined,and the frequency control system of synchronous motor in the control frame is studied in depth.Based on the establishment of the mathematical model in MT two-phase rotating coordinate system,the current controller,speed controller,excitation controller and magnetic chain controller of the synchronous motor frequency control system are designed respectively according to the vector control strategy of synchronous motor.Finally,the fuzzy PID controller of the compressor outlet pressure cascade control system is designed.Furthermore,simulation is executed by Matlab software.The simulation results show that comparing with the conventional PID controller,the outlet pressure control system of the electric drive compressor unit designed in this paper has better static and dynamic performance.