Permanent magnet synchronous motor sensorless control rotor position angle compensation method

Abstract

The invention discloses a permanent magnet synchronous motor sensorless control angle compensation method. The method comprises the steps of establishing a permanent magnet synchronous motor voltage model based on an alpha-beta two-phase static coordinate system, and constructing a sliding mode observer according to the permanent magnet synchronous motor voltage model based on the alpha-beta two-phase static coordinate system; inputting a stator current and a stator voltage in the alpha-beta two-phase static coordinate system into the sliding mode observer to iteratively output the alpha-axis and beta-axis current error switching signals, obtaining the estimated values of the counter electromotive force for observing an alpha axis and a beta axis according to the alpha-axis and beta-axis current error switching signals, and then processing to obtain an estimated value of a rotor position angle; and constructing an estimated gamma delta rotating coordinate system, and compensating the estimated value of the rotor position angle under the gamma delta rotating coordinate system. The method can effectively solve the problem that the control performance is reduced due to the estimated angle error when the motor is in a high-speed area, and improves the estimation precision of the rotor position angle.

Description

technical field [0001] The invention relates to a method for controlling a permanent magnet synchronous motor, in particular to a method for compensating a position angle of a rotor controlled by a permanent magnet synchronous motor without a position sensor. Background technique [0002] Permanent magnet synchronous motors have the characteristics of high power density, simple structure, and small moment of inertia, so they are widely used in aerospace, rail transit, and CNC machine tools. [0003] The installation of position sensors for permanent magnet synchronous motors will increase the volume of the motor system, and it is difficult to use mechanical position sensors on some ultra-high-speed permanent magnet synchronous motors. Therefore, the position sensorless control technology of permanent magnet synchronous motors has become a research hotspot in recent years. The position sensorless control method of the permanent magnet synchronous motor only needs to sample th...

AI Technical Summary

Problems solved by technology

However, in the process of observing the back electromotive force or flux linkage, it is generally necessary to use a low-pass filter, and the introduction of the low-pass filter will inevitably bring a certain phase error

Although some current algorithms avoid the use of low-pass filters, under high-speed conditions, digital control delays, dead zone effects, inverter nonlinearity and other factors will also cause certain current and voltage signal phase errors, which greatly reduces Without the accuracy of the position sensorless approach, using the wrong position signal can also lead to degraded motor performance

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