Decoupling Correction Method for Asynchronous Motor Rotor Resistance and Exciting Inductance

Abstract

The invention discloses an asynchronous motor rotor resistance and excitation inductance decoupling correction method. The method comprises the steps of obtaining accurate counter electromotive force e via a high-order sliding-mode observer according to the acquired and calculated motor stator voltage vector V, stator current vector i and rotor electrical angular velocity omega r under a two-phase static coordinate system alpha beta, and establishing an asynchronous motor state space expression according to the relation between the counter electromotive force and the rotor flux, thus realizing accurate observation of a rotor flux vector phi r; obtaining a rotor flux vector calculation value which is defined in the specification according to a current flux model, then obtaining a phase difference delta theta and an amplitude difference which is defined in the specification, analyzing and deducing a correlation function of a parameter error and a flux error to obtain a weighting coefficient, correcting given rotor resistance which is defined in the specification in the system by using a decoupling correction function I which is defined in the specification, and correcting given excitation inductance in the system by using a decoupling correction function II which is defined in the specification. The method does not have the flux transient problem while solving the problem of integration of flux acquisition, and can obtain an accurate rotor time constant and realize on-line identification of the excitation inductance.

Description

Technical field [0001] The invention relates to an on-line correction method for asynchronous motor parameters, in particular to a decoupling correction method for asynchronous motor rotor resistance and excitation inductance. Background technique [0002] Asynchronous motor is a kind of high-order multivariable nonlinear strong coupling system, and the application of vector control makes it obtain the speed regulation performance of DC motor. Indirect vector control obtains the synchronous speed through the addition of the rotational speed and the slip frequency, and then obtains the flux linkage orientation angle. The vector control algorithm is simple, easy to implement in engineering, and has good stability, so it is a widely used vector control scheme. The accuracy of slip frequency calculation depends entirely on the accuracy of the rotor time constant, and this parameter usually deviates from its nominal value due to factors such as temperature, magnetic saturation, eddy ...

AI Technical Summary

Problems solved by technology

In this paper, the flux linkage is obtained through the steady-state model of the voltage, and based on this, an online correction scheme for the excitation inductance and rotor time constant is designed. Although the integral problem of the flux linkage is overcome, the transient performance of the correction scheme is limited by the calculation of the flux linkage. influences

[0006] In summary, none of the existing technologies can achieve online correction of parameters and orientations.

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