Asynchronous motor parameter online correction method based on rotor flux observer

Abstract

The invention discloses an asynchronous motor parameter online correction method based on a rotor flux observer. The method is characterized by comprising the following steps: getting an accurate counter electromotive force e through a high-order current sliding-mode observer according to a motor stator voltage vector v, a stator current vector i and a rotor electrical angular velocity omega(r) under a two-phase static coordinate system (alpha-beta) obtained through acquisition and operation; setting up an asynchronous motor state space expression based on the relationship between the counter electromotive force and the rotor flux; constructing a rotor flux sliding-mode observer according to the space expression to observe a rotor flux vector phi(r); getting the calculated value phi<hat>(ri) of the rotor flux vector according to a current flux model; and further getting the phase difference sinusoidal quantity sin(delta theta) and the amplitude difference delta|phi(r)|; and using the phase difference sinusoidal quantity sin(delta theta) to correct a given rotor resistance R<hat>(r) in the system, and using the amplitude difference delta|phi(r)| to correct a given excitation inductance L<hat>(m) in the system. The integral problem caused by flux is overcome. Moreover, there is no transient flux problem, an accurate rotor time constant can be obtained, and online identification of excitation inductance is realized.

Description

Technical field [0001] The invention relates to an on-line correction method for asynchronous motor parameters, in particular to an on-line 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 cu...

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Problems solved by technology

To this end, people have made various efforts, such as "A Method for Accurate Orientation of the Rotor Magnetic Field Based on Reactive Power Vector Control of Asynchronous Motors", Lu Haifeng, Qu Wenlong, Zhang Lei, etc., Chinese Journal of Electrical Engineering, 2005 No. 25 Articles on pages 116-120 of Volume 6, and titled "Slip Frequency Correction for Indirect Vector Control of Asynchronous Motors Based on Rotor Flux q-axis Component", Fan Yang, Qu Wenlong, Lu Haifeng, et al., Proceedings of the Chinese Society for Electrical Engineering, 2009 Articles on pages 62-66 of Vol. 29, No. 9, 2010; these two articles respectively proposed an online correction scheme for flux orientation based on reactive power and quadrature component of rotor flux. The former uses the deviation of reactive power to adjust the rotor time The constant is used for online correction, and the latter uses the quadrature component of the rotor flux linkage to achieve correction, but both correction algorithms are affected by the excitation inductance

[0004] Titled "A Method of Using Torque Observation to Correct the Magnetic Field Orientation of the Asynchronous Motor's Rotor", Yan Junfeng, Wang Xiaolin, Liao Qixin, the article of the Chinese Journal of Electrical Engineering, Volume 35, Issue 7, 2015, pages 4517-4523; The moment model refers to self-adaptation to correct the slip frequency, but this scheme is greatly affected by the load

[0005] Titled "Indirect Vector Control of Electric Vehicle Asynchronous Motor Based on Parameter Online Correction", Zhang Jie, Chai Jianyun, Sun Xudong, et al., an article on pages 90-96 of the Journal of Electrotechnical Society, Vol. 29, No. 7, 2014; The flux linkage was obtained, and based on this, an online correction scheme for the excitation inductance and rotor time constant was designed. Although the integral problem obtained by the flux linkage was overcome, the transient performance of the correction scheme was affected by the calculation of the flux linkage.

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

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