A full-speed range sensorless control method for surface-mounted permanent magnet synchronous motors

Abstract

The invention discloses a method for controlling a permanent-magnet synchronous motor in a full-speed range without position sensors in a surface-mounted mode. The method includes firstly, injecting pulsating high-frequency voltage signals into an axis of a two-phase rotation estimation coordinate system, scanning the permanent-magnet synchronous motor within a 360-degree electric injection angle range and recognizing the initial position of the permanent-magnet synchronous motor according to high-frequency feedback currents of the axis; secondly, tracking the position of the permanent-magnet synchronous motor in real time according to the high-frequency feedback currents of the axis; thirdly, controlling the permanent-magnet synchronous motor in a medium and high-speed range and a low-speed range without the position sensors by a pulsating high-frequency injection process and a sliding-mode observer process and selecting control processes according to an instruction speed and an actual speed so as to control the permanent-magnet synchronous motor in the full-speed range without the position sensors. The method has the advantages that the two control processes supplement each other, so that the control performance can be improved to a certain extent as compared with the control performance when each control process is used individually, the dependence of the sliding-mode observer process on parameters of the motor is cast off, the influence of the high-frequency injection process on a sliding-mode observer and original control for the permanent-magnet synchronous motor is eliminated, and a perfect strategy for controlling the permanent-magnet synchronous motor in the full-speed range without the position sensors in the surface-mounted mode is provided.

Description

technical field [0001] The invention relates to the field of vector control of permanent magnet synchronous motors, in particular to a position sensorless control method in the full speed range of a surface-mounted permanent magnet synchronous motor. Background technique [0002] The permanent magnet synchronous motor has been more and more widely used because of its high power factor and outstanding load capacity, and its development direction has also changed from ordinary small and medium-sized to miniaturization and high power. The photoelectric encoder as a position detection element is a conventional configuration for precise control of permanent magnet synchronous motors, but the existence of encoders increases the connection and interface circuits between the motor and its control system, making the system susceptible to interference and affecting the reliability of the entire system Sex, which limits the application range of permanent magnet synchronous motors; in a...

AI Technical Summary

Problems solved by technology

[0005] However, the pulse vibration high-frequency injection method has complex algorithms, difficult signal processing, and high requirements for hardware processing capabilities, so it is difficult to implement

Moreover, when the speed rises to the medium-high speed range, the delay of the position and speed generated by the filter will affect the dynamic performance of the speed control, and tracking failure may occur, and the influence of the dead zone effect will also reduce the estimation accuracy. In addition, the impact of the truncation error generated during the DSP operation will also be highlighted

Therefore, the application of the pulse vibration high-frequency voltage injection method can only realize position sensorless control in the range of zero speed and low speed, and cannot be applied to the range of medium and high speeds.

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