Research And Implementation Of DC Motor Speed Regulation System For Cold Rolling Pipe Mill

Cold rolling pipe mill is the key equipment to produce high quality metal pipe.DC motor is usually used to provide power for rolling pipe production.Considering the frequent starting and stopping of main motor,fast changing of load,this paper studies the methods of DC motor excitation and speed control to get stable excitation and speed control in cold rolling mill production.At last,this paper completes relevant system based on DSP and mobile phone.Firstly,this paper discussed the mathematical model of DC motor and the application requirements of DC motor in cold rolling pipe production.Because the Excitation and the Armature winding of DC Motor are separated,this paper introduces the control of the excitation for motor.Because the control of motor excitation depend on the parameter of motor excitation winding model,this paper then discussed the measurement method for parameters of the excitation winding model.At last,this paper analysed the influence of measurement deviation on system control.Double closed-loop speed control system has been widely used in the control of DC motor.This paper introduces the parameter tuning of PI controller for current loop and speed loop,and analyses the influence of model parameter deviation on system control.To solve the problem that PI controller will lead to overshoot of the system,this paper introduced IP controller in speed loop control.The theoretical analysis shows that the response speed and overshoot of PI controller are faster than that of IP controller,but their anti-disturbance performance is basically the same.In order to improve the control performance,a disturbance observer is introduced into the double closed-loop control.It can help solve the problems of large load variation and large fluctuation of motor speed in the production.The theoretical study shows that better anti-disturbance performance can be obtained by using P+DOB controller in the speed loop.By adjusting the filter coefficients of the disturbance observer and the proportional controller coefficients of the speed loop,the response speed and anti-disturbance performance of the P+DOB controller can be adjusted.Finally,the hardware and software components of DC speed regulation system are introduced.With Bluetooth connected to DC speed regulator,operators can use flat panel or mobile phone to get the real-time operation of the motor and complete the parameter tuning of the controller.