Current Harmonic Suppression Technology Of High Speed Permanent Magnet Synchronous Motor

High-speed Permanent Magnet Synchronous Motor(HS-PMSM)has obvious advantages of high-speed,high power density and fast dynamic response speed.It has been widely used in machine tool spindles,air compressors,vacuum pumps,distributed power generation and flywheels Energy storage and other fields.In this paper,the current harmonic suppression of high-speed permanent magnet synchronous motor drive control system is taken as the research object.Aiming at the problems of complex current harmonic generation factors,high-frequency loss content calculation difficulty,suppression algorithm research difficulty when considering dynamic performance and complex design of special drive controller.The research on the electrical parameter change law of high-speed permanent magnet synchronous motor,the influence factors and variation law of time / space current harmonic,the influence law of current harmonic on high-frequency loss,the model predictive current harmonic suppression algorithm and the design of special digital drive controller are carried out.Firstly,according to the electromagnetic structure design criteria of high-speed permanent magnet synchronous motor,the variation law of electromechanical parameters of high-speed permanent magnet synchronous motor is obtained.Based on the analysis of the influence of electromechanical parameters on transient current harmonics and control system performance,a comprehensive analysis and judgment method for highspeed PMSM has been obtained.Secondly,in order to realize the accurate quantitative analysis of current harmonics of high-speed permanent magnet synchronous motor(PMSM),it is necessary to establish an accurate simulation model for the high-speed PMSM control system.In this paper,a modeling method of precise control system simulation model considering the discretization of control system software and frequency division of current loop / speed loop is proposed.The current harmonic variation and distribution of actual motor model and ideal motor model under the action of PWM inverter and ideal voltage source are compared and analyzed,and the influence factors of spatial / time harmonic on current spectrum distribution of high-speed permanent magnet synchronous motor are revealed.In addition,in order to obtain the optimal suppression criterion of high-frequency loss of high-speed permanent magnet synchronous motor,it is necessary to study the variation of high-frequency loss of high-speed permanent magnet synchronous motor with the amplitude and frequency of harmonic current.A finite element calculation method is proposed to calculate the high frequency loss under the action of any harmonic current.The high-frequency losses under the excitation of different current sources are analyzed,and the variation law of stator core loss and rotor eddy current loss with harmonic current amplitude and frequency is obtained.Furthermore,the influence of different topologies on the high frequency loss is obtained,which provides a theoretical basis for the selection of special driver topology and switching frequency.Thirdly,in order to achieve the comprehensive suppression of current harmonics in high-speed PMSM,a model predictive current harmonic suppression algorithm based on Sliding Fourier Transform on-line current identification method is proposed to achieve the mutual suppression of low-frequency current harmonic and current harmonic near the switching frequency.The Sliding Fourier Transform algorithm is used to identify the amplitude of current harmonics on-line.The switching state and output voltage vector simplification principle of neutral point clamped three-level topology are designed.The synthesis of dynamic control performance and current harmonic suppression capability is constructed.The evaluation weight function realizes the comprehensive optimal control of high-speed PMSM dynamic performance and current harmonic suppression.Finally,the design of high-speed permanent magnet synchronous motor drive controller is optimized,including the calculation performance of the driver controller,the three-level modulation method and the anti-interference current sampling method.An improved three-level modulation method which redefines the meaning of duty cycle is proposed to reduce the requirement of three-level modulation for of high-performance microchip peripheral modules.A current integral sampling method based on hardware integration circuit is proposed to eliminate the influence of current harmonics caused by transient current of high-speed permanent magnet synchronous motor.High performance TMS320C6747 is used for the operation processing core.The specialized drive controller and the experimental platform are completed.On this basis,based on the traditional twolevel drive control platform and the designed high-speed PMSM specialized drive controller,the performance of the current sampling integrate method,the high-speed PMSM current harmonic variation law and the high-frequency loss variation law with the driver parameters,the model predictive current harmonic suppression algorithm are compared and verified.