Detection method for position of rotor in full-speed domain of permanent magnet synchronous motor without position sensor

Abstract

The invention discloses a detection method for position of a rotor in a full-speed domain of a permanent magnet synchronous motor without a position sensor. The detection method mainly comprises a high-frequency signal injection method, an extended back electromotive force method and a switching method. When the motor is stationary or operates at a low speed, the high-frequency signal injection method is used for estimating the position of the rotor, and the switching method is designed, so that when back electromotive force is large enough, the high-frequency signal injection method is switched to the extended back electromotive force method to estimate the position of the rotor. According to the detection method disclosed by the invention, the two methods are effectively integrated through the designed switching method, so that the detection method for the position of the rotor of the permanent magnet synchronous motor without the position sensor can be used in a full-speed range and is high in detection precision and easy to implement.

Description

technical field [0001] The invention relates to a position sensorless control technology of a permanent magnet synchronous motor, in particular to a position sensorless permanent magnet synchronous motor rotor position detection method in the full speed range. Background technique [0002] In order to control the position of the permanent magnet synchronous motor, it is necessary to continuously detect the position of the motor rotor during its operation. Generally speaking, mechanical sensors are used to detect the position of the rotor, but the use of mechanical sensors affects the performance of permanent magnet synchronous motors, so the rotor position detection technology without using sensors has become a research field of permanent magnet synchronous motor control. key problem. The existing methods are mainly divided into three types: rotor position detection technology based on permanent magnet synchronous motor model calculation, rotor position detection technology...

AI Technical Summary

Problems solved by technology

Since the amplitude of the back EMF is proportional to the speed, it is difficult to detect the back EMF at low speeds, so the back EMF method is not suitable for use at low speeds

When the motor is running at high speed, the high-frequency signal injection method will cause system vibration and torque ripple, which will affect the accuracy of position estimation and the stability of the motor operation, so the high-frequency signal injection method is not suitable for high-speed use

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