Sensorless control method for permanent magnet synchronous motor based on sliding mode observer

Abstract

The invention discloses a sensorless control method for a permanent magnet synchronous motor based on a sliding mode observer, which specifically comprises the following steps: firstly, according to amathematical model of a surface-mount permanent magnet synchronous motor in a two-phase stationary coordinate system, using an observation error of stator current as a sliding mode surface to write asliding mode current observer equation; then, carrying out the stability analysis of the sliding mode current observer equation; based on the sliding mode current observer, constructing a back electromotive force observer equation on the basis of a back electromotive force model for separating a back electromotive force signal and then estimating the rotor position and rotational speed, and carrying out the stability analysis of the back electromotive force observer equation; secondly, based on the sliding mode current observer, identifying the stator resistance of the motor; and finally, adjusting the feedback gain in real time according to the running speed of the motor. The sensorless control method for the permanent magnet synchronous motor based on the sliding mode observer in the invention solves the problem that the chattering phenomenon of the observation signal in the sliding mode observer existing in the prior art is big, low-pass filtering and rotor angle compensation are required, and the observation precision is not high.

Description

technical field [0001] The invention belongs to the technical field of motor position sensorless control, and in particular relates to a position sensorless control method of a permanent magnet synchronous motor based on a sliding mode observer. Background technique [0002] Permanent magnet synchronous motors have been widely used in industrial fields due to their good physical properties, suitability for operation in a wide speed range, and high power density. Although the position and speed of the rotor can be used to precisely control the permanent magnet synchronous motor, installing a position sensor will bring some problems, such as increasing the cost of the system and reducing the reliability of the system. In order to solve this problem, the position sensorless control of permanent magnet synchronous motor has become a research hotspot, and many position sensorless control strategies have been proposed. Sliding Mode Observer (Sliding Mode Observer, SMO) is easy to...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a position sensorless control method for permanent magnet synchronous motors based on sliding mode observers, which solves the problem that the observed signal chattering phenomenon in the sliding mode observers in the prior art is relatively large, and rotor angle compensation is required And the problem of low observation accuracy

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