Method for measuring initial position of rotor of permanent magnetic synchronous motor

Abstract

The invention relates to a method for measuring initial rotor position of permanent magnet synchronous motor which comprises steps of: applying constant voltage space vector on motor armature winding; applying constant voltage pulse for judging initial rotor magnetic pole pointing direction; applying a first voltage pulse and A phase upper bridge arm conducting, B and C phase lower bridge arm conducting and having the same conducting width with A phase. In the conducting duration, A phase current is target current for detecting A phase current peak value; and then detecting and calculating each phase target current in sequence; comparing current variance ratio on the three windings, the rotor magnetic pole axis has the shortest distance with the axis of the phase with the greatest current variance ratio, the direction and changed current direction are consistent.

Description

Technical field [0001] The invention relates to a permanent magnet synchronous motor, in particular to a method for measuring the initial rotor position of the motor. Background technique [0002] The accuracy of the initial rotor position judgment of a permanent magnet synchronous motor is directly related to whether the motor can start smoothly and whether it can be started with the maximum torque. [0003] The existing method of measuring the initial rotor position of a permanent magnet synchronous motor is to form an equivalent flux linkage circle in the air gap of the motor by applying a constant voltage space vector to the armature winding of the motor, and then detect the corresponding The armature current transforms the phase current into the current component in the dq coordinate system, and compares the d-axis current under the action of each voltage vector. The angle of the voltage vector corresponding to the maximum current is the initial position angle of the rotor. ...

AI Technical Summary

Problems solved by technology

[0008] However, when this method is applied in practice, sometimes there will be such a problem: the actual angle is θ angle, and the result obtained by the above method may be θ+180° or θ-180°, or even other In this way, even with a more accurate hardware circuit and a more complex software algorithm, because the base θ is wrong, there will be a problem of large estimation error or even estimation failure

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