Magnetizing method and device for permanent-magnet motor

Abstract

The magnetization method of the permanent magnet type motor related to the present invention includes: the first to the third inductance measurement steps (S201 to S203) of measuring the inductance involved in the combination of the two phases in the three-phase winding; according to the three inductance measurement values ​​( 1st to 3rd inductance measurement values), the step of specifying the relative positional relationship between the rotor and the stator (S205); A step of magnetizing the unmagnetized magnetizable member (S205 to S210). Therefore, even if the internal structure of the compressor cannot be seen, the relative position of the rotor and the stator can be accurately aligned with a small device, and the magnetization method and device of the permanent magnet type motor can be magnetized without magnetization.

Description

technical field [0001] The invention relates to a permanent magnet motor, in particular to a magnetization method and device for its rotor. Background technique [0002] A conventional permanent magnet motor includes a stator that generates a rotating magnetic field by applying current to a winding mounted on a stator core made of a magnetic material, and a rotor that has permanent magnets that are rotatably disposed in the stator core. From the viewpoint of energy saving, permanent magnet motors are widely used, for example, as motors for compressors of air conditioners. [0003] When the permanent magnet type motor is assembled, when the rotor is inserted into the stator, the magnetic parts of the rotor are magnetized, and under the action of its strong magnetic force, the rotor is often attracted to the inner peripheral surface of the stator core and becomes immovable. The locked state makes it difficult to insert the rotor into the stator. [0004] For this reason, the...

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Problems solved by technology

[0010] However, when alignment is performed using jigs, visual inspection, and image processing, there is a problem that alignment cannot be performed if the positional relationship between the stator and rotor inside the compressor is in a structure that cannot be seen.

[0011] In addition, when energizing for alignment, the rotor must be moved by energizing the winding, so the amount of current energizing the winding increases.

In addition, in this method, in order to obtain the accuracy necessary for position integration, it is necessary to further increase the current value

In this way, since the amount of current increases, the temperature rise increases, and there is also a problem that a large-capacity device is required, and a large-scale device is required.

[0012] In addition, although the method disclosed in Patent Document 1 has the advantage of integrating the magnetization position even if the internal structure of the compressor cannot be seen, there is a change in the inductance value caused by the rotation of the rotor, which affects the resolution of the equipment that measures it. When the value is not large, the error included in the detection of the rotor angle indicating the peak value becomes large.

As a result, when the change in inductance value is small, the optimum magnetization position cannot be detected, and good magnetization cannot be performed.

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