Position recognition method of rotor of alternating current permanent magnet synchronous motor

Abstract

The invention discloses a position recognition method of a rotor of an alternating current permanent magnet synchronous motor. The position recognition method comprises the following steps: step 1: selecting a plurality of flux angles and exciting the motor by stator current corresponding to the flux angles under an open ring state; taking a specific DAC (Digital-to-Analog Converter) signal waveform as an exciting waveform; recording an acceleration signal of the motor; step 2: removing a low-frequency signal in the acceleration signal; step 3: calculating an initial position of the rotor of the motor. According to the position recognition method disclosed by the invention, the motor is excited by the stator current corresponding to the flux angles under the open ring state, and the motor is excited by utilizing the specific DAC signal waveform as the exciting waveform, so that a movement distance of the motor can be reduced and the motor can be adaptive to any occasion; the position recognition method has the advantages that the time for angle detection and recognition of the rotor of the motor is very short and does not exceed 100ms and the working efficiency is greatly improved.

Description

technical field [0001] The invention relates to the field of power electronics technology and system identification, in particular to a method for identifying the position of an AC permanent magnet synchronous motor rotor. Background technique [0002] In an AC servo motor, the electromagnetic torque of the motor is expressed by the following formula: [0003] m e =k t [i a cos(θ r )+i b cos(θ r +2π / 3)+i c cos(θ r -2π / 3)] [0004] Among them: M e Indicates the electromagnetic torque generated by the motor, i a i b and i c Respectively, the phase current of the motor, k t is the torque constant, θ r Indicates the electrical angle of the motor rotor. [0005] Among them, the phase current i of the motor a i b and i c Can be expressed as follows: [0006] i a = I q cos(θ' r ); [0007] i b = I q cos(θ′ r +2π / 3); [0008] i c = I q cos(θ′ r -2π / 3); [0009] Among them, I q is the torque command current, θ’ r is the measured electrical angle of th...

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Problems solved by technology

[0012] Therefore, in the actual servo control system, the detection of the rotor position of the AC permanent magnet synchronous motor is very important. If the rotor position of the AC permanent magnet synchronous motor cannot be detected more accurately, the consequences will reduce the output of the motor Torque, let the motor overheat, heavy will produce positive feedback, resulting in serious equipment damage

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