Transformation Of DC Speed Control System Based On Bottom Type Drilling Platform

This article mainly research how victory rig 4 on the basis of the original SCR simulation control cabinet,using full digital dc speed regulating device(6RA70)and programmable controller(S7-300PLC)and intelligent from centralized control station(ET200M)of digital network,the two winch dc motors,six sets of mud pump dc motor and a wheel dc motor drive control.The controlled by digital DC speed regulating device contained in the 6RA70 instead of the original analog control board,the corresponding digital controller interface circuit with the original system interface to be able to join,to achieve the goal of control of silicon controlled rectifier bridge.Because it is series motor,so the control of the series motor will be a key in the process of implementation of this project.In the digital controller,through what kind of software design,achieve the objectives of the double closed loop controller.By serial communication mode to realize the collection of data and control instructions,instead of the original intermediate relay to achieve analog control circuits,by DP communication mode to realize information transfer between the PLC master station and slave station.Based on 6RA70 digital dc speed regulating device for parameter setting,optimize the motor running,to achieve the optimal operation parameters.With 6RA70 device parameter unit-PMU – 2,can monitor the running status of the dc motor,dc speed regulating device can also be parameter Settings.6RA70 device can also be the failure of a store and make judgments,convenient for on-site technical personnel to the fault diagnosis and processing.6 ra70 device control system of high accuracy,fast response speed,speed of static and dynamic performance is good.In this paper,the main work includes:(1)the overall hardware scheme of digital controller to replace analog controller design;(2)the digital controller to control dc motor is commonly bottom-supported dc motor,excitation is changeless,by regulating speed,better control,because we are using is series motor,so the control will be very difficult;(3)digital controller software design,namely,the software implementation of the double closed loop controller,speed loop use fuzzy PI controller;...