| With the rapid development of power electronics technology and modern control theory,the performance of Permanent Magnet Synchronous Motor(PMSM)speed control system has been increasing and is widely used in aerospace,autonomous navigation vehicles,robotics,and other industrial fields.However,the PMSM is a complex,strongly coordinated,nonlinear system,which is susceptible to uncertainties in actual operating conditions such as motor parameter uptake,load variation,and load torque-induced rotational inertia variation.This paper combines sliding mode control,disturbance compensation technique,and rotational inertia identification method to study the PMSM speed control system,and the details are as follows:(1)The structure of the motor is introduced with the surface-mounted permanent magnet synchronous motor as the object of study.The transformation relations of natural coordinate system,synchronous rotating coordinate system and stationary coordinate system are studied,and then the mathematical model and equations of motion of the motor are derived.The space vector pulse width modulation technique is elaborated.Combined with the vector control strategy,the vector control system of PMSM is built to provide the basis for the subsequent algorithm research.(2)In order to further improve the response speed and anti-disturbance of the PMSM speed regulation system,a non-singular fast terminal sliding mode controller based on a super-twisting extended state observer is proposed.Firstly,a non-singular fast terminal sliding mode controller based on a new variable exponential reaching law is designed to address the contradiction between chattering and reaching speed.This reaching law introduces variable gain functions and power functions related to the system state variables and adaptively adjusts the reaching speed according to the distance of the state variables from the equilibrium point.Then,this reaching law is applied to the design of improved non-singular fast terminal sliding mode controllers Secondly,in the actual speed control process,the PMSM has external disturbances caused by load torque changes and internal disturbances caused by internal parameter uptake,which make the system stability performance and robustness weaken.To solve these problems,combining a model-independent extended state observer and a strongly robust super-twisting algorithm,a super-twisting extended state observer is proposed,it achieved fast observation of system disturbance and compensation of the disturbance estimates to a non-singular fast terminal sliding mode controller to enhance the system’s anti-disturbance performance.Finally,the above design method is verified by simulation.(3)The change of external load torque will cause a large change of system rotational inertia,resulting in slower response and lower control accuracy of the system,and the overall control performance of the motor drive system is affected.To solve this problem,an improved Model Adaptive Reference Control(MARC)algorithm is proposed to identify the rotational inertia online.Firstly,this paper investigates the identification of rotational inertia of permanent magnet synchronous motor based on MARC algorithm,and the influence of adaptive gain in the algorithm on the motor rotational inertia identification results is analyzed.Secondly,aiming at the conventional fixed adaptive gain coefficient that makes it difficult for the algorithm to meet the stability and rapidity requirements of rotational inertia identification at the same time,a MARC algorithm with a variable adaptive gain is designed,which can automatically adjust the value of the adaptive gain based on the difference between the current moment and the previous moment’s parameter identification result.Finally,the moment of inertia identification result is fed back to the controller and observer in real time,which further improves the dynamic response performance of the PMSM speed regulation system.(4)Based on the design method of this paper,a motor control system platform with RTUBOX204 real-time digital controller as the core is built for verification.Firstly,the Rtunit system with RTU-BOX204 real-time digital controller as the core is introduced,and the specific hardware design scheme of the experimental platform is given.Secondly,the software design of the experimental platform is carried out,and the design block diagram of the software design process and its important modules is given.Then,the traditional algorithm,the algorithm after improving the approximation law,and the algorithm after increasing disturbance compensation are experimentally compared under different working conditions,and the moment of inertia identification results under the corresponding working conditions are given.Finally,according to the obtained experimental data to prove the effectiveness of the design method of this paper. |
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