Double-observer switching operation method and system based on full-speed domain of permanent magnet synchronous motor

Abstract

The invention provides a dual-observer switching operation method based on a full-speed domain of a permanent magnet synchronous motor. The dual-observer switching operation method adopts a motor, a high-speed observer and a low-speed observer, and comprises the following steps: S1, selecting a working speed region of a motor; S2, judging the working speed region of the motor, and outputting information by adopting a corresponding observer; S3, acquiring a voltage signal and a current signal output by a current loop PI regulator, performing linear conversion on the voltage signal and the current signal, and then feeding back, wherein the voltage signal comprises a direct-axis voltage Ud and a quadrature-axis voltage Uq, and the specific calculation comprises the following steps: solving anangle difference delta[theta] between the angle [theta]1 of a dq1 coordinate system and the angle [theta]2 of a dq2 coordinate system, and respectively calculating the projections of the output voltage and current signals under the dq1 coordinate system under the dq2 coordinate system. According to the method, the coordinate system switching logic in the transition process is operated, so that the stability of the system is guaranteed in the switching process, and no current impact exists; and instantaneous switching of the observer can be realized under the condition of not causing sudden change of current.

Description

technical field [0001] The invention relates to the field of permanent magnet synchronous motor control, in particular to a dual-observer switching operation method based on full-speed non-inductive control of permanent magnet synchronous motors. Background technique [0002] In the process of sensorless full-speed control of permanent magnet synchronous motors, different observers are used for the low-speed section and the medium-high speed section to observe the position angle and speed of the motor rotor. The low-speed section generally uses an open-loop drag scheme or a scheme based on motor high-frequency model estimation; while the medium-high speed section generally uses a scheme based on motor fundamental wave model estimation, such as back electromotive force estimation and flux linkage estimation. However, in the transition process of low speed and medium high speed, there is a problem that the rotor position angle and speed information observed by the two observer...

AI Technical Summary

Problems solved by technology

When the motor accelerates rapidly, passing through the w1~w2 speed range in a very short time, it will cause a sudden change in the system angle, which will cause a sudden change in voltage and current, which will affect the stable and reliable operation of the system

In short, the disadvantage of the existing technology is: when the system runs in the w1~w2 speed range for a long time, it will cause the output of the observer to oscillate and even cause the observer to be unstable, which will lead to abnormal vibration of the motor and even loss of control

[0004] In the field of sensorless control of permanent magnet synchronous motors, two control schemes are mostly used at present: (1) Three-stage starting method, first pre-positioning, and then open-loop dragging of the motor with a fixed I / F curve (the dragging process It is a position open loop, there is no rotor position angle and speed feedback, so it will have the characteristics of long start-up time and poor anti-disturbance performance)

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