A servo control method for a permanent magnet linear motor

Abstract

The present invention discloses a permanent magnet linear motor servo control method. According to the method, a position loop and a q-axis current loop constitute a position current controller; a speed loop and q-axis current constitute a speed current controller; the position current controller and the speed current controller output q-axis voltage reference Uq by adopting a parallel control mode; d-axis current outputs d-axis voltage reference Ud by adopting PI control; after Uq and Ud are subjected to Park transformation, a control quantity Ualpha and a control quantity Ubeta are outputted; Ualpha and Ubeta are subjected to SVPWM (space vector pulse width modulation), so that six paths of pulse signals are outputted; the six paths of pulse signals are subjected to three-phase inversion carried out by six power switch tubes of a three-phase inversion power source; and finally three-phase voltage applied to a three-phase permanent magnet linear motor is outputted, and control on the three-phase permanent magnet linear motor can be realized. With the method of the invention adopted, the stability, precision and dynamic response of a linear motor servo control system can be improved.

Description

Technical field [0001] The invention relates to a permanent magnet linear motor servo control method, which belongs to motor servo and control technology. Background technique [0002] The linear motor has the advantages of direct drive, high thrust, high rigidity and long stroke, and has become the first choice for advanced machining in the machine tool industry at home and abroad. In the machine tool feed servo system, compared with the original rotary motor, the linear motor cancels the mechanical mechanism of the motor and the worktable, shortens the transmission chain, so as to achieve high-speed response of direct drive, reduce mechanical friction and tracking lag, Improve the efficiency and accuracy of the machine tool. Due to the cancellation of the transmission device, the linear motor can realize instantaneous start and instantaneous stop at high speed, which is well used in high-speed cutting. [0003] According to the requirements of control accuracy and dynamic perfo...

AI Technical Summary

Problems solved by technology

The three-loop control system includes a position loop, a speed loop, and a current loop, which form a series control system. The three-loop control system has strong anti-interference ability and strong load capacity. Since the adjustment of the outer loop of the position needs to go through the speed loop and the current loop, it will cause lag adjustment. , resulting in a tracking error

[0004] Due to the existence of cogging effect, end effect, system parameter (mover mass, viscous friction coefficient, etc.) changes, thrust fluctuation and other nonlinear factors in permanent magnet linear motor, the linear motor system is a multivariable and time-varying nonlinear system , in demanding servo control occasions, it is difficult for traditional PID controllers to meet precise control requirements

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