JP3752789B2 - Inspection method for permanent magnet motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for inspecting a stator winding of a permanent magnet motor that uses a reluctance torque in addition to a magnet torque by adopting a rotor structure having a reverse saliency.
[0002]
[Prior art]
Conventionally, a permanent magnet motor that uses reluctance torque in addition to magnet torque has been known by forming a rotor structure with reverse saliency by embedding a permanent magnet in a rotor core made of a high permeability material such as iron. It has been. FIG. 7 is a structural cross-sectional view of a permanent magnet motor having reverse saliency as a structure for effectively utilizing reluctance torque and having three-phase four-pole windings. In this permanent magnet motor, a rotor 2 is configured by embedding permanent magnets 3a and 3b in a rotor core 7 formed of an iron core of a high magnetic permeability material or laminated electromagnetic steel plates. The rotor 2 generates magnet torque and reluctance torque by a rotating magnetic field generated by the winding 5 applied to the stator 1 to rotate the rotor 2.
[0003]
In addition, since it takes a lot of labor to incorporate the magnetized rotor 2 into the stator 1, the permanent magnet 3 a is obtained by instantaneously passing a large current through the winding 5 of the stator 1 after the rotor 2 is assembled into the stator 1. , 3b is magnetized. Thereafter, in order to inspect whether the winding 5 of the stator 1 is abnormal when magnetized, a surge voltage is applied to the winding 5 to inspect the impedance variation of the winding.
[0004]
[Problems to be solved by the invention]
However, in the above configuration, reluctance torque acts when magnetizing, and rotational torque acts on the rotor 2 to shift the rotational direction position of the rotor 2 in some cases. When the rotor position is shifted, the impedance as viewed from the winding changes, which causes a problem that the abnormality of the winding 5 cannot be detected. In order to solve the problem, it was necessary to add an operation for correcting the positional deviation of the rotor after magnetization.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention magnetizes the rotor by flowing a magnetizing current through the stator winding in a state where the rotor is incorporated in the stator, and then flows a DC current through the stator winding, thereby After the position of the rotor is determined by the attracting action of the electromagnet to be produced and the permanent magnet of the rotor, a surge is applied to the stator winding to inspect the impedance variation of the winding. Further, a direct current in the same direction as the magnetizing current is passed through the stator winding. By doing so, it becomes possible to prevent demagnetization of a permanent magnet. If the magnitude of the direct current is too large, the reluctance torque may cause a large misalignment. Therefore, it is preferable that the direct current be set to a minimum magnitude that can correct the misalignment of the rotor.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, in a permanent magnet motor having reverse saliency, the rotor is magnetized by flowing a magnetizing current through the stator winding in a state where the rotor is incorporated in the stator, and then the stator winding. After DC current is passed and the rotor position is determined, a surge voltage is applied to the stator winding to inspect the impedance variation of the winding, and there is no impedance variation seen from the winding due to rotor misalignment. It becomes possible to accurately detect a change in impedance due to a line abnormality.
[0007]
According to a second aspect of the present invention, in the permanent magnet motor inspection method according to the first aspect, a direct current in the same direction as the magnetizing current is passed through the stator winding to determine the position of the rotor. For correction, the rotor is not demagnetized even when a current is passed through the winding.
[0008]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0009]
1 and 3 are diagrams showing an embodiment of the present invention. With the rotor 2 incorporated in the stator 1, a magnetizing current is passed through the stator winding 5 with the connection as shown in FIG. 1, and after magnetizing the rotor, the winding 5 applied to the stator 1 in FIG. As shown in FIG. 1, when a direct current is passed through the two phases, a magnetic flux flows in the direction of the arrow shown in FIG. 2, and the attraction of the rotor 2 with the permanent magnets 3a and 3b causes the rotor 2 of FIG. The rotor 2 moves to the position and is positioned. 2 and x of the winding 5 in FIG. 2 indicate that currents opposite to each other flow.
[0010]
Thereafter, as shown in FIG. 3, a surge voltage as shown in FIG. 4 is applied to the winding 5 of the stator 1 to inspect the variation in impedance of the winding 5.
[0011]
The direct current for positioning the rotor 2 is set in the same direction as the magnetizing current. If the magnitude of the direct current is too large, the position of the rotor 2 may be greatly displaced due to the reluctance torque. Therefore, it is preferable to set the magnitude of the direct current to a minimum that can correct the position deviation of the rotor 2.
[0012]
FIG. 5 is a diagram showing another embodiment. In a state where the rotor 2 is incorporated in the stator 1, a magnetizing current is passed through the stator winding 5 with the connection as shown in FIG. 5, and after magnetizing the rotor, a DC current is passed from one phase to the other two phases. Like FIG. 2, magnetic flux flows in the direction of the arrow shown in FIG. 6, and the rotor 2 moves to the position of the rotor 2 in FIG. 6 and is positioned by the attraction action with the permanent magnets 3a and 3b of the rotor 2. The
[0013]
Thereafter, as shown in FIG. 3, a surge voltage as shown in FIG. 4 is applied to the winding 5 of the stator 1 to inspect the variation in impedance of the winding 5.
[0014]
In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.
[0015]
【The invention's effect】
According to the first aspect of the present invention, since the rotor can be inspected at a constant rotational position, there is no variation in impedance viewed from the winding due to the rotor misalignment. It becomes possible to accurately detect a change in impedance.
[0016]
According to the second aspect of the present invention, since the direction of the current flowing through the winding for determining the rotor position is the same as the magnetizing current, there is an effect that the rotor is not demagnetized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a sectional view of a motor showing an embodiment of the present invention. FIG. 3 is a block diagram showing an inspection of impedance variation of a stator winding according to the present invention. 4 is a diagram showing a surge voltage waveform of the present invention. FIG. 5 is a diagram showing another embodiment of the present invention. FIG. 6 is a cross-sectional view of a motor showing another embodiment of the present invention. Also, a configuration diagram of a permanent magnet motor that uses reluctance torque.
1 Stator 2 Rotor 3a, 3b Permanent magnet 5 Winding

Claims (2)

In a permanent magnet motor having reverse saliency, the rotor is magnetized by passing a magnetizing current through the stator winding while the rotor is incorporated in the stator, and then a DC current is passed through the stator winding to determine the position of the rotor. After that, a method for inspecting a permanent magnet motor in which a surge voltage is applied to the stator winding to inspect the impedance variation of the winding. 2. The inspection method for a permanent magnet motor according to claim 1, wherein a DC current in the same direction as the magnetizing current is passed through the stator winding to determine the position of the rotor.

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