Research On The Weakening Speed Regulation Strategy Of Permanent Magnet Synchronous Electric Spindle Based On Advanced Control Algorithm

In high-speed machining,computer numerical control?CNC?machine of high precision and speed is a crucial component.Meanwhile,in the system of CNC machine,permanent magnet synchronous motor spindle?PMSMS?is an important unit.On comparison to regular three-phase asynchronous motor spindle,PMSMS is highlighted with advantages in limited heat generation and moment of inertia,and great power density,power factor,power to volume ratio,and speed of response in the stage of machine start-up.In addition,machining error caused by thermal deformation can be reduced by PMSMS,allowing for high precision and high speed processing.With the support by grants from the National Natural Science Foundation of China "Research on Driving Performance and Intelligent Control of Hybrid Drive Motor Spindle"?No.51405209?,lateral scientific research "Research and Development of High Speed and High Precision Permanent Magnet Synchronous Motor Spindle"?No.KYH17002?,and Jiangsu graduate innovation?No.SJCX17₀753?,present work focuses on simulation and analysis of the algorithm of high-speed permanent magnet synchronous motorized spindle.The main content is as follows:In order to meet the requirements of processing accuracy and speed,the corresponding algorithm in the flux weakening control of PMSMS was studied.Firstly,the mathematical model of PMSMS was established to analyze factor limiting electric spindle speed.A lead angle flux weakening speed regulation method is proposed as a solution to above issue.After that,the specific variation process among the current,the speed and the torque during the flux weakening speed regulation of the electric spindle,as well as the modulation method adopted by the inverter were analyzed.Finally,the synthesis principle of the modulation algorithm and the relationship among the variables were given,followed by implemention using Matlab.In order to improve the steady-state and dynamic performance of PMSMS in the process of flux weakening,schemes such as fuzzy control and sliding mode control were proposed to adjust system rotatory speed.Fuzzy control can dynamically fuzz the output value of the controlled object,enabling restrainment of the change of internal parameters and internal and external noise interference of the control system.This makes the system obtain strong robustness.Sliding mode control can make the system running following its own programmed trajectory.With the right sliding surface,sliding mode control can make the system quickly approach to a stable state.,In addition,the self-setting of sliding mode in the process of sliding mode control design,can make the system exhibiting strong robustness.Thanks to the strong coupling and non-linearity significances of PMSMS,the application of fuzzy control and sliding mode control can provide good outcomes.It is suggested the usage of PI controller in the current regulator of the PMSMS flux weakening speed regulation system can enhance its dynamic performance and provide a perfect parameter adjustment scheme.Via establishment and derivation of the transfer function model of the current loop of the PMSMS,the current loop regulator of the motorized spindle was corrected to a typical type I link.Finally,the adjustment formula of the current loop regulator parameters was derived,along with establishment of C# program to facilitate the setting of regulator parameters based on different motor spindle parameters.In order to verify the validity and correctness of the theoretical analysis,the flux weakening of speed control system was established by Matlab/Simulink.The additional load and disturbance of the CNC machine were simulated to verify the control performance of the fuzzy control and fuzzy sliding mode switching control algorithm.The simulation results verified that the fuzzy control and fuzzy sliding mode switching control algorithm have excellent static and dynamic performance,along with characteristics of convenience and ease of operation in the parameter adjustment process.These results are of great significance for the machine tool efficiency improvement.