Research On Permanent Magnet DC Motor Speed Control System Based On Active Disturbance Rejection Control And Its Speed Sensorless Scheme

DC motor has a series of advantages,such as a good velocity modulation characteristic,high starting and braking torque,and overload capacity,so it has been playing an important role in the field of transmission.During the operation of the speed control system,the armature resistance,armature inductance and load of the motor may change with the different working conditions,resulting in the change of the speed.The traditional PI control has some inhibitory effect on the disturbance,but it is powerless to deal with large amplitude and fast change.This paper studies the Active Disturbance Rejected Control(ADRC)method of DC speed control system composed of permanent magnet DC motor,which is of great significance to improve the anti-jamming ability and the dynamic response.Based on the reading of a large number of literatures,in this paper,the ADRC control scheme based on ESO is studied in detail in the case of permanent magnet DC motor speed control system used in steam welding of inverter welding machine.The main research contents are as follows:(1)Firstly,the basic operation principle,structural characteristics,mathematical model and control scheme of permanent magnet DC motor are introduced.(2)The basic working principle and characteristics of ESO are discussed in detail.The design of Linear Extended State Observer(LESO),especially the method of parameter determination,is discussed in depth.Then,a second-order LESO is designed for the DC drive system,and the estimation information of the total disturbance of the velocity loop is obtained.(3)Taking the speed control system composed of permanent magnet DC servo motor as an example,according to the information of disturbance observed by LESO,the DC speed control system based on ADRC is designed.Taking into account the possible problems of ADRC,the paper also describes the use of tracking differential(Tracking Differentiator,TD)solution.The simulation results of the prototype verify the effectiveness of the scheme.(4)In view of the fact that the armature current of the DC motor contains the commutation information and the commutation information can be utilized as the rotational speed information of the rotor,instead of the photoelectric encoder or the resolver for detecting the rotor position,and the control scheme without the mechanical position sensor can be realized.This paper presents a novel speed sensorless velocity measurement scheme based on armature current commutation information.Taking into account the rotor speed and armature current for the program to achieve the process involved in many of the problems,the corresponding solutions are put forward and the prototype is produced to verify the effectiveness of the scheme,which lays the foundation for the final realization of the speed sensorless speed control system.