Study On Hydraulic Loading System Driven By Permanent Magnet Servo Motor

For the past few years,with the development of the permanent magnet servo motor control theory and variable voltage variable frequency technology,a new type electro-hydraulic servo system whose driven core is permanent magnet servo motor has appeared.This system without the participation of servo valve and proportional valve,is called no valve type electro-hydraulic servo system,or the direct-drive pump controlling electro-hydraulic servo system.Compared with the traditional servo system,this system has many advantages,like flexible control,energy efficiency,simple structure,low noise pollution,low cost,strong ability to resist pollution,etc.As the direct-drive pump controlling electro-hydraulic servo system has so many advantages,there would be a lot of social benefits and economic benefits,if we go to study this system and improve the performance of this system.Considering the working principle of hydraulic system and new type direct-drive pump controlling electro-hydraulic servo system,the main task of his essay is to study the control precision of the direct-drive pump controlling electro-hydraulic servo system whose driving source is permanent magnet servo motor.In this paper,the main research work has the following three points:(1)Through consulting a large number of domestic and foreign related literature and data,I have a general understanding of new type direct-drive pump controlling electro-hydraulic servo system’s current research status.To study the control principle of new type of servo control system,the design of the hydraulic control system and electric control system,and to select hydraulic components and electrical components.(2)The action process of a new type of servo system is analyzed,using the Siemens STEP7-Micro/win software writing the basic logic control program and PID control program with PI control algorithm as the core program,using WinCC software to complete the design of control interface of this system.(3)According to the principle diagram of the electrical schematic diagram and hydraulic structures,the control test bench has been built.From stability,rapidity,and accuracy,three aspects of system,we can analyze the new type servo system.Finally,from the experiments,we can prove that the system ’s stability is relatively good,its steady state error is 4%,and its response time is 0.3-0.4s.