Method and system for detecting rotor magnetic pole initial position of permanent magnet synchronous machine

Abstract

The present invention relates to a method for a method for detecting initial position of a permanent magnet synchronous motor rotor, including the steps of (a) setting hypothesis magnetic pole position; (b) inputting d0 shaft current into the motor for periodic variation of positive direction and negative direction, the motor being static during the period; (c) judging whether the accumulation current of the d0 shaft is more than a presetting threshold value or not during a period, if 'yes', implementing step (d); otherwise implementing step (e); (d) regulating the hypothesis magnetic pole position based on the polar of the d0 shaft accumulation current and implementing step (b); (e) determining the hypothesis magnetic pole position being the rotor initial position, detection being over. The invention also provides a corresponding system. The invention obtains the initial position angle of the rotor magnetic pole before starting up the motor using the characteristics of the permanent magnet synchronous motor, thus maximum rotary torque starting of the permanent magnet synchronous motor can be implemented with vector control mode.

Description

technical field [0001] The invention relates to a permanent magnet synchronous motor, more specifically, to a method and system for detecting the initial position of the rotor magnetic pole of the permanent magnet synchronous motor. Background technique [0002] In order to achieve excellent control performance, AC permanent magnet synchronous motors generally adopt closed-loop vector control methods. A key issue in the vector control of permanent magnet synchronous motors is the need to obtain the exact position of the rotor poles. Usually, when obtaining the magnetic pole position, an absolute position encoder needs to be connected to the motor shaft end to detect the speed and magnetic pole position of the permanent magnet synchronous motor. However, for incremental encoders without absolute position signals, the initial position of the magnetic poles cannot be obtained when the motor starts. It is necessary to open-loop control the motor to rotate first, and the vector...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is to provide a method and system for detecting the initial position of the rotor magnetic poles of the permanent magnet synchronous motor in view of the defect that the initial position detection algorithm of the permanent magnet synchronous motor is complicated or the accuracy is not high when there is no absolute position encoder

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