Control method and system for permanent magnet synchronous motor based on current prediction

A permanent magnet synchronous motor, current prediction technology, applied in the direction of motor generator control, electronically commutated motor control, control system, etc., can solve the problems of low current ripple, poor parameter robustness, difficult installation, etc., and achieve efficient operation , Improve the effect of system stability

CN102790575AInactive Publication Date: 2012-11-21HUAZHONG UNIV OF SCI & TECH
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2012-11-21
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a control method for a permanent magnet synchronous motor based on current prediction and belongs to the field of control over permanent magnet synchronous motors. The method mainly comprises the steps of predicting the improved current and identifying the sensorless rotating speed and a corner based on a phase-locked ring idea combined with the predicting step. According to the control method, the current of a motor stator is predicted ahead of a switch period according to the detected current of the motor stator and a current instruction; corresponding control voltage is predicted; and motor rotating speed and corner position information is identified according to the estimated counter electromotive force of the motor. The invention further provides a control system for realizing the control method. The control system comprises a rotating speed regulator, a current predicting unit, a counter electromotive force estimation unit, a controller and a space vector modulating unit. According to the control method and the control system disclosed by the invention, the permanent magnet synchronous motor can be enabled to still safely operate at high efficiency when the parameters change; and the control method and the control system have a favorable application prospect in the field of control over the permanent magnet synchronous motor.
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Description

Technical field

[0001] The present invention relates to a permanent magnet synchronous motor control strategy, and in particular to a permanent magnet synchronous motor control method based on phase-locked loop (PLL) sensorless and current prediction. Background technique

[0002] Direct-drive permanent magnet wind turbines have many advantages over doubly-fed wind turbines in terms of operating efficiency, reliability, grid-connected control, fault ride-through, etc. In addition, the price of permanent magnet materials has dropped in recent years, making them rapidly become a variable speed constant frequency wind turbine. An important development direction in the field of wind power generation. In a direct-drive wind power generation system, the motor-side converter realizes energy conversion between wind energy and electric energy by controlling the rotation speed of the generator. However, the wind has the characteristics of "coming in and out and changing at any time". ...

Examples

Embodiment Construction

[0021] The technical concept of the present invention is: analyze the mathematical model of the permanent magnet synchronous motor, obtain the torque equation, the voltage equation, the flux equation, and the motion equation of the motor based on the model, and obtain the motor under ideal conditions according to the digital control theory and the deadbeat control theory. Control equations or control block diagrams. Consider the actual problems of motor digital control: the system has sampling delay, algorithm operation delay, motor parameters are not suitable for accurate acquisition, and motor parameters will change during operation. It is necessary to correct the motor control equation under ideal conditions: combined with predictive control algorithm, Predict the output current of the motor one switching cycle in advance, and predict the output control voltage command on this basis, so as to offset the delay caused by system sampling and calculation; by properly processing ...