Method for inhibiting speed fluctuation, control device and compressor control system

Abstract

The invention discloses a method for inhibiting speed fluctuation of a permanent magnet synchronous motor. The method includes the steps of: obtaining a target rotating speed omega_ref, a feedback rotating speed, and a fluctuation rotating speed delta(omega), a q axis inductor Lq and a permanent magnet flux linkage (phi)f of the permanent magnet synchronous motor; performing PI adjustment on delta(omega) to obtain a q axis reference current Iq_ref, and obtaining a q axis target voltage Ud* according to Iq_ref, omega_ref, delta(omega) and (phi)f; performing PI control on a q axis actual voltage according to Ud* so as to obtain a q axis compensating current Iq_add; obtaiing a d axis target voltage Ud* according to Iq_ref, Iq_add, omega_ref, delta(omega) and Lq, and performing PI control on a d axis actual voltage according to Ud* to obtain a d axis compensating current Id_add; superposing Iq_add and Iq_ref to perform feedforward compensation on a q axis current, and superposing Id_add and a d axis reference current to perform feedforward compensation on a d axis current. The inhibition method can realize effective inhibition of speed fluctuation in operation of the permanent magnet synchronous motor by performing feedforward compensation on the d axis current and the q axis current. The invention also discloses a control device of the permanent magnet synchronous motor and a compressor control system.

Description

technical field [0001] The invention relates to the technical field of PMSM (Permanent Magnet Synchronous Motor, permanent magnet synchronous motor) control, in particular to a method for suppressing speed fluctuation of a permanent magnet synchronous motor, a control device for a permanent magnet synchronous motor, and a permanent magnet synchronous motor with the permanent magnet synchronous motor The compressor control system of the control device of the synchronous motor. Background technique [0002] When controlling the permanent magnet synchronous motor, it is necessary to suppress the speed fluctuation of the permanent magnet synchronous motor during operation. Suppressing the speed fluctuation can relatively suppress the noise and vibration, improve the comfort of the customer, and also prevent the motor from being suddenly loaded or unloaded. Occurs when the motor is out of step under load. [0003] In the related art, the following problems exist in the control t...

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Problems solved by technology

[0004] 1. The bandwidth of the speed loop is low, and it is easy to get out of step during sudden loading and unloading, and the speed fluctuates greatly. It takes a long time to stabilize the speed. It is not suitable for some special occasions such as servo motor control

At present, the common practice in the industry is to increase the bandwidth of the speed loop, but it brings about large speed ripple, easy speed overshoot, and no bandwidth suitable for all frequency bands and various load conditions;

[0005] 2. Periodic loads will cause motor speed fluctuations. For example, if the speed fluctuations caused by compressor loads are not suppressed, vibrations will occur. Long-term operation of the air conditioner in the case of large vibrations is prone to the risk of pipe cracks, which has a negative impact on the quality of the air conditioner. Serious impact

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