Initial absolute position detection method for permanent magnet synchronous motor rotor

Abstract

The invention discloses an initial absolute position detection method for a permanent magnet synchronous motor rotor. The method comprises the steps that the sector of the magnetism of the motor rotoris determined according to a U signal, a V signal and a W signal which are output by a code disc, the digital value corresponding to the middle of the sector is taken as the initial position of the rotor, and the position of a rotor flux and the position of the voltage vector are positioned; an armature induction flux and the rotor flux interact with each other and enable the rotor to be meshed at the initial position, the position is not always the true initial position of the motor rotor, initial positioning of the position of the motor rotor is just achieved, the output current of the motor at the moment is slightly larger than the current output during accurate positioning, a position error compensation algorithm is triggered after a first Z signal output by the encoder comes, and then a relative error in initial positioning is eliminated, that is to say, the position of the rotor is accurately positioned. According to the method, the absolute position information of the magneticpole of the rotor can be accurately detected, the requirement that the motor is started from a static state is met, and implementation is easy.

Description

technical field [0001] The invention belongs to the field of electromechanical technology, and relates to a method for detecting an initial absolute position of a rotor of a permanent magnet synchronous motor. Background technique [0002] The initial absolute position information of the rotor of the permanent magnet synchronous motor is a necessary condition for the speed loop to start and operate stably. Usually, an incremental pulse encoder is installed on the motor to provide the position information of the rotor, so that the closed-loop control of the system can be realized. When the device is powered on for the first time, it can only obtain the relative position of the motor rotor, but cannot provide the initial absolute position information of the motor. When the absolute initial position of the rotor is unknown, directly starting the permanent magnet synchronous motor will cause the motor to stall or shake violently. The most common method of initial positioning of...

AI Technical Summary

Problems solved by technology

Obtaining the initial position of the rotor magnetic poles by using the magnetic characteristics of the motor rotor can not avoid the problem of rotor vibration during the starting process

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