A Method for Harmonic Observation and Torque Ripple Suppression of Permanent Magnet Synchronous Motor

Abstract

The invention discloses a method for observing flux linkage harmonics of a permanent magnet synchronous motor and suppressing torque ripple, and relates to the field of drive of permanent magnet synchronous motors for new energy vehicles. The invention observes the counter electromotive force harmonic wave f in real time through the extended state observer Ed , f Eq , and the back electromotive force harmonic compensation is performed on the input end, so that the output current of the permanent magnet synchronous motor has no harmonics, and the interference of the harmonic current to the control system is avoided. At the same time, according to the observed back EMF harmonic f Ed , f Eq Calculate the harmonic compensation current, and cooperate with the output current of the permanent magnet synchronous motor to obtain the harmonic compensation voltage. It can be seen from the simulation results that the flux linkage harmonic observation and torque ripple suppression method designed in the present invention is effective. Compared with other torque ripple suppression strategies, the present invention can realize permanent magnet synchronous motor torque ripple without installing additional hardware facilities, without building an accurate torque ripple model and calculating complicated harmonic compensation current effective suppression.

Description

technical field [0001] The invention relates to the drive field of permanent magnet synchronous motors for new energy vehicles, in particular to a method for observing flux harmonics of permanent magnet synchronous motors and suppressing torque ripple. Background technique [0002] In the process of design and manufacture, due to the influence of the rotor pole structure of the permanent magnet synchronous motor, the ideal sine wave cannot be achieved, resulting in a large number of high-order harmonics in the motor flux linkage. These factors are reflected on the permanent magnet synchronous motor, which will make the electromagnetic torque output by the permanent magnet synchronous motor pulsate. [0003] On the one hand, torque pulsation will generate electromagnetic noise, reduce the control performance of the drive system, and cause speed fluctuations during the operation of the permanent magnet synchronous motor; on the other hand, in some vehicle operating conditions,...

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Problems solved by technology

[0009] 1. For the torque ripple suppression of the permanent magnet synchronous motor drive system, the schemes reported in the literature usually need to build an accurate torque ripple model isomorphically, and calculate the harmonic current that needs to be compensated according to the model to generate additional torque ripple Suppress the electromagnetic torque ripple of the permanent magnet synchronous motor itself. Therefore, the harmonic compensation current calculated by this scheme when the parameters of the permanent magnet synchronous motor are inaccurate cannot effectively suppress the torque ripple;

[0010] 2. The existing methods often only focus on improving the tracking performance of the current loop and the speed loop to achieve the purpose of smooth output of the speed, and have not effectively suppressed the electromagnetic torque ripple inside the permanent magnet synchronous motor;

[0011] 3. When the existing methods are faced with inaccurate parameters of permanent magnet synchronous motors, the solutions usually require a lot of calculations or the continuity of control is not enough

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