The Research On High-Speed Spindle Induction Motor Drive Control

The high-speed spindle induction motor drive system is an important component ofhigh-performance CNC machine, its performance requires not only has excellent dynamicand static performance, but also need high-speed, high precision and high stability. Thispaper research on high-speed spindle induction motor flux-weakening control technology,and the analysis&measurement of the rotor time constant (Tr).System select the current model of the rotor flux oriented under MT coordinates,based on IFOC; current loop uses current vector decoupling controller to improve theresponse and stability of the torque current and flux current; voltage output uses SVPWMmethod and dead-time compensation to reduce the six harmonics of current and motornoise; flux control based on voltage feedback loop flux-weakening control strategy. Byvoltage feedback and improvement of the control structure, system reduces the sensitivityof the flux-weakening parameters and simplifies algorithm. Using over-modulationtechnique can enhance the output of motor torque, and it can automaticallyover-modulation only when overloaded, to optimize the efficiency of the motor.This paper also studies the impact of the rotor time constant’s error on field-oriented,MARS and torque curves. Drawing conclusion that the error of Tr has little impact ontorque using closed-loop flux-weakening method. And introduces three new types of theTr measurement methods: torque current symmetry method, the current step measuringmethod and the magnetizing current measurement, they direct measure the Tr by torquecurrent, stator voltage and flux current, with high accuracy and good practicality.Finally, Matlab simulation and physical experiments verify the theoretical analysisand system performance, and put forward the further works.