Speed fluctuation suppression method applicable to permanent-magnet synchronous motor

Abstract

The invention belongs to the technical field of control and optimization of a permanent-magnet synchronous motor, and discloses a speed fluctuation suppression method applicable to a permanent-magnetsynchronous motor. The speed fluctuation suppression method comprises the following steps of (1) calculating a speed error; (2) acquiring an instruction current according to the speed error; (3) processing the sampled instruction current by employing a lowpass filter; (4) taking instruction current data as compensation quantity data, and extracting an instruction current point; (5) performing interpolation operation on the extracted instruction current point, and superposing a torque current compensation value obtained by calculation to the instruction current at an interrupt moment each time;(6) extracting an instruction current sampling point from the instruction current calculated again after superposition, and repeating the steps (3) to (5); and (7) controlling the permanent-magnet synchronous motor to run by a pulse width modulation wave obtained according to the newly-obtained and superposed instruction current and a feedback current of the motor. The speed fluctuation suppression method is small in operation, the compensation accuracy is improved, and the noise is reduced.

Description

technical field [0001] The invention belongs to the related technical field of permanent magnet synchronous motor control optimization, and more specifically relates to a speed fluctuation suppression method suitable for permanent magnet synchronous motors. Background technique [0002] At present, the use of servo drives to control permanent magnet synchronous motors will encounter the problem of large speed fluctuations at low speeds. This problem is mainly affected by the control algorithm and the structure of the motor. The effect and the number of pole pairs have a more pronounced effect on the torque, causing the motor speed to fluctuate with the motor rotational position. Cogging torque is the torque generated in the circumferential direction by the interaction of the permanent magnet magnetic field of the rotor with the cogging of the stator core. The cogging torque has nothing to do with the current of the stator, it always tries to position the rotor in some posit...

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Problems solved by technology

[0003] The methods for reducing motor fluctuations in the prior art mainly include the following: 1. Adopt the coordinate transformation method, carry out coordinate transformation for the 5th, 7th, 11th, and 13th harmonics existing in the relative current and convert them to the coordinate system d, q axis, and after filtering, inverse transformation is performed to compensate the static coordinate system, thereby acting on the motor to reduce the speed fluctuation. However, this method has a large amount of calculation, and the number of supplementary harmonics is fixed, so it is not flexible enough; 2. Multi-layer neural network is applied to the speed fluctuation compensation of permanent magnet synchronous motor, but this method does not meet the real-time requirements of engineering

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