Method for controlling direct torsion/ flux linkage of permanent magnet synchronous motor

Abstract

The invention discloses a method for controlling direct torsion / flux linkage of a permanent magnet synchronous motor. The method comprises the steps of collecting three-phase stator voltage and currents of the motor, and obtaining voltage and currents under a two-phase static coordinate system through three-phase / two-phase static coordinate conversion; calculating actual feedback value of electromagnetism torsion and stator flux linkage according to the voltage and the currents under the two-phase static coordinate system; obtaining initial given value of the electromagnetism torsion through a PI controller according to difference between given rotating speed and feedback rotating speed; obtaining given value of the electromagnetism torsion and the stator flux linkage according to a given electromagnetism torsion and stator flux linkage calculating module; obtaining given voltage on an alpha beta shaft of the two-phase static coordinate system through a given voltage calculating module; generating switching signals of an inverter through space vector pulse width modulation, triggering a switching device of the inverter, and realizing direct torsion / flux linkage control of the permanent magnet synchronous motor. The method realizes low, medium and high speed wide range operation of the permanent magnet synchronous motor, does not need to rotate coordinate conversion, and has the advantages of being convenient to calculate, quick in dynamic response, strong in robustness, and the like.

Description

technical field [0001] The invention belongs to the technical field of permanent magnet synchronous motor control, and in particular relates to a direct torque / flux linkage control method of a permanent magnet synchronous motor. Background technique [0002] Compared with asynchronous motors, permanent magnet synchronous motors have the advantages of high efficiency, high power factor, small size, light weight, and low temperature rise, so they have attracted extensive attention from scholars at home and abroad. The traditional direct torque control of permanent magnet synchronous motor has the problem that the torque will drop when the field is weakened at high speed, that is, after the stator flux linkage is weakened to a certain value, the torque angle exceeds its limit value, resulting in the torque and The ratio of the torque angle changes from positive to negative, and the normal torque cannot be provided, causing the motor to run unstable and unable to achieve high-sp...

AI Technical Summary

Problems solved by technology

However, vector control needs to change the rotating coordinates, the calculation is complicated, and the dynamic performance is not as good as that of direct torque control.

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