JP7153437B2 - Rotating electric machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to rotating electric machines such as electric motors, generators, and induction motors, and in particular, rotating electric machines that are driven at a high voltage that causes partial discharge and that include mica as an insulator, which has durability against partial discharge deterioration. Regarding.

From the viewpoint of saving energy, saving resources, and reducing the burden on the environment, miniaturization of rotating electric machines and shortening of manufacturing lead time are cited as one of the important issues. 2. Description of the Related Art In recent years, in order to reduce the materials used in rotating electric machines, development of downsizing technologies for rotating electric machines has become active.

As one means of downsizing technology, thinning (or simplification) of insulation for improving heat dissipation is becoming important. In addition, if it becomes possible to reduce the thickness of the insulation from the viewpoint of reducing the manufacturing running cost, the process of taping the insulation can be shortened, and excessive equipment operation can be suppressed.

However, thinning (or simplification) of the insulation increases the electric field between the coil and the core, causing discharge with a large amount of electric charge, which may impair the reliability of the rotating electric machine. Therefore, it is necessary to ensure high insulation while reducing insulation thickness.

In the conventional technology, for example, in a rotating electrical machine for a vehicle with a rated voltage of about 1 kV, a plurality of bar-shaped strands coated with glass insulation are bundled together and solidified, and mica tape is applied to the surface layer of the bundle of insulated strands. It is mainly configured to be wound (see Patent Document 1, for example). In addition, in general industrial rotating electric machines with a high voltage of 3 kV or higher, a configuration is adopted in which a mica tape is wound on the surface layer of a bundle of a plurality of strands coated with mica insulation (see, for example, Patent Document 2).

JP-A-8-19201 JP-A-60-200510

As described in Background Art, in recent years, miniaturization and simplification of the manufacturing process of rotating electric machines have become important issues, but it is necessary to properly balance them with reliability. On the other hand, the progress of insulating material technology is also remarkable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rotating electric machine capable of achieving both miniaturization of equipment, optimization of insulation life, and reduction of manufacturing cost.

To give an example of the "rotating electric machine" of the present invention,
A rotating electric machine comprising a rotor and a stator, wherein the stator is composed of a stator core and stator coils mounted in slots of the stator core, wherein the stator coils are composed of strands of wire. An insulated wire composed of a conductor and a wire insulation that is a first insulator coated on the surface of the wire conductor is wound and bundled to form a winding bundle, and a second wire is wound around the wire bundle. The main insulation that is an insulator is formed, the wire insulation that is the first insulator is a wound tape-shaped insulator, and the main insulation that is the second insulator is , A tape-shaped insulator is wound, and an insulator containing mica or an insulator composite with nanoparticles or sub-nanoparticles, which has high insulation performance for the wire insulation that is the first insulator, is used, An insulator containing a glass material having lower insulating performance than the first insulator is used for the main insulator, which is the second insulator.

Advantageous Effects of Invention According to the present invention, it is possible to provide a rotating electric machine capable of achieving both miniaturization of equipment, optimization of insulation life, and reduction of manufacturing cost.

1 is a cross-sectional view showing the entire rotary electric machine including a stator; FIG. 2 is a vertical cross-sectional view of the stator coil of the rotating electrical machine of Example 1. FIG. FIG. 10 is a vertical cross-sectional view of the stator coil of the rotating electrical machine of Example 2; FIG. 11 is a vertical cross-sectional view of a stator coil of a rotating electrical machine of Example 3;

FIG. 1 is a cross-sectional view of the entire rotary electric machine in the direction of the rotation axis (shaft), which is common to all the embodiments. In addition, in each drawing for describing the embodiments, the same component is given the same name and reference numeral, and the repeated description thereof is omitted.

The rotating electric machine includes a rotor 9 that is attached to a rotating shaft (shaft) 8 and rotates, and a stator 2 that is arranged around the rotor 9 .

The stator 2 is composed of a stator core 4 and a stator coil 3 attached to the stator core 4 . The stator core 4 is constructed by laminating a plurality of thin electromagnetic steel plates in the axial direction, and a plurality of slots extending in the axial direction are formed on the inner diameter side of the stator core 4 at predetermined intervals in the circumferential direction. The linear portions of the stator coils 3 are mounted in these slots. Further, although not shown, a stator frame for supporting the outer diameter side of the stator core 4, end plates fixed to both ends of the stator frame in the axial direction, and the rotating shaft 8 are attached to the end plates. Equipped with supporting bearings.

A first embodiment of the rotating electric machine of the present invention will be described below with reference to FIG. FIG. 2 shows a cross-sectional view of the stator coils 3 mounted in the slots 5 of the stator core 4. FIG.

The stator coil 3 is formed by winding an insulated wire 15 composed of a wire conductor 10 and a wire insulation 11 (first insulation) formed on the surface of the wire conductor 10 to form a winding bundle. A main insulation 12 (second insulation) is formed on the surface of the wire bundle having the wire insulation 11 . The stator coil 3, as shown in FIG.

In the manufacture of the stator coil 3, first, the wire insulation 11 is wound around the chamfered rectangular copper conductor (the wire conductor 10). Then, the insulated wires 15 are bundled in a number corresponding to the electrical design. For the reason described later, a solidifying material 20 is interposed between the strands. After winding these wire bundles with the main insulation 12 (second insulation), the entire stator coil 3 is impregnated with epoxy resin and fixed.

The wire insulation 11 is configured by winding, for example, a mica tape having high insulation performance. This is because electric fields tend to concentrate at corners and gaps in the vicinity of the coil due to its geometric structure, and discharges tend to occur. .

As shown in FIG. 2, a blanking material 20 is typically used between adjacent insulated coils. This is to prevent the coil from coming apart during coil drawing and bending.

When the straight portion 31 of the stator coil 3 is mounted in the slot 5 , the stator coil 3 to which the main insulation 12 is applied is fitted with a wedge (not shown) on the opening side of the slot 5 so as to firmly fit in the slot 5 . to support.

For the main insulation 12, which is the second insulation layer, an insulation material having insulation properties lower than that of the wire insulation 11 is applied. This is because the electrical stress in the second insulation region is lower than that in the wire insulation 11, which is the first insulation. Also, from the viewpoint of manufacturing cost, it is desirable to use a simpler and less expensive insulating material because the main insulation 12, which is the second insulation, has a larger area to be insulated.

For the main insulation 12, a material having low insulation performance, such as a glass tape, is applied. Even if the insulation performance is lower than that of the mica-wrapped insulation, there is no problem as long as the entire rotating electrical machine satisfies the insulation test. Manufacturing costs can be reduced by prioritizing products that require a short manufacturing lead time.

In the conventional structure, porous glass insulation is applied to the first insulation where partial discharge occurs frequently, which accelerates partial discharge deterioration, but in this embodiment, mica insulation with excellent partial discharge resistance is used for the first insulation. Therefore, it becomes possible to alleviate discharge deterioration. By using a material with high insulation performance for the first insulation, the thickness of the main insulation, which is the second insulation, can be reduced, and the overall thickness of the insulator can be reduced. . Also, by reducing the thickness of the main insulation, the winding amount of the insulating tape can be reduced, making it possible to shorten the manufacturing lead time. In the conventional structure, mica tape was used for the main insulation, but in this embodiment, relatively inexpensive glass insulation is used for the main insulation, so that the manufacturing cost can be reduced.

According to this embodiment, by using mica tape with high insulation performance for the wire insulation, it is possible to shorten the manufacturing lead time and downsize the equipment while strengthening the insulation near the coil, and it is inexpensive as the main insulation. By using such a glass tape, it is possible to reduce the manufacturing cost.

A second embodiment of the rotating electric machine of the present invention will be described below with reference to FIG.

As in the first embodiment, the wire insulation 11, which is the first insulation, is made of an insulating material that is superior in insulation performance to the main insulation 12, which is the second insulation. For example, as in the first embodiment, mica tape is applied to the first wire insulation 11, and relatively inexpensive glass tape is applied to the main insulation 12, which is the second insulation. However, in Example 2, the solidifying material 20 provided between the insulating wires 15 provided in Example 1 is not used.

This is because the reason why the hardening material 20 is provided is to prevent the occurrence of weak points (air gaps, voids, etc.) in the insulation surface due to variations in the coil arrangement. This is because there is no problem even if some variation occurs due to the high strength of .

According to this embodiment, since no hardening material is provided, it is possible to shorten the manufacturing lead time and reduce the manufacturing cost.

A third embodiment of the rotating electrical machine of the present invention will be described below with reference to FIG.

This embodiment is provided with an insulation optimization configuration corresponding to an inverter surge in an inverter-driven machine. An inverter (power conversion device) performs high-speed switching to output a rectangular wave, and a surge voltage is generated due to the steep rise of the waveform. In inverter-driven machines, most of the surge voltage is transiently applied to the first turn of the stator coil near the lead, so it is necessary to strengthen the insulation there.

In an inverter-driven rotating electric machine, a material with the highest insulating properties is applied to the wire insulation 111 of the first turn near the lead of the stator coil 3 . An insulating material having an insulating property equal to or lower than that of the first turn is applied to the wire insulation 11 of the other turns. For example, for a low-voltage machine, mica winding insulation is applied only to the wire insulation 111 of the first turn, and glass winding insulation is applied to the other wire insulations 11 .

According to this embodiment, in the inverter-driven electric rotating machine, a material with excellent insulation is used for the wire insulation of the first turn near the lead of the stator coil, so that the insulation is strengthened against surge voltage. can do. Also, by using a material with lower insulating properties than the first turn for wire insulation of other turns, the manufacturing cost can be suppressed.

As a material having high insulating performance to be used for the wire insulation 11, an insulating material obtained by composite of nanoparticles or sub-nanoparticles may be used in addition to the mica material. Insulating materials composited with nanoparticles or sub-nanoparticles extend the life of the insulator by lengthening the discharge degradation path due to the fine structure of the nanoparticles.

Let the insulation design electric field and thickness of the first insulator be a1 (V/m) and b1 (m) respectively, and the insulation design electric field and thickness of the second insulator be a2 (V/m) and b2 (m) respectively. I will explain the insulation design.

Here, when the insulation is designed so as to satisfy the relationship a1×b1>a2×b2, the design electric field value is a limited value, and a large insulation distance is required for the first insulator. This makes it possible to reduce local electrical stress that may occur in the first insulator. Localized stress is due to the coil angle R, voids and delamination.

Each of the above explanations has been given with examples of rotating electric machines such as electric motors for vehicles and general industrial use and wind power generators, but it is of course applicable to rotating electric machines in general, such as electric motors and generators in other fields. .

2... Stator 3... Stator coil 31... Straight part 32... Coil end part 4... Stator core 5... Slot 8... Rotating shaft (shaft)
9... Rotor 10... Wire conductor 11... Wire insulation (first insulation)
12... Main insulation (second insulation)
15... Insulated wire 20... Hardening material 111... Wire insulation of first turn

Claims (7)

A rotating electric machine comprising a rotor and a stator, wherein the stator comprises a stator core and stator coils mounted in slots of the stator core,
In the stator coil, an insulating wire composed of a wire conductor and a wire insulation that is a first insulator coated on the surface of the wire conductor is wound and bundled to form a winding bundle. A main insulation, which is a second insulator, is formed around the winding bundle,
The wire insulation that is the first insulator is a tape-shaped insulator wound around,
The main insulation, which is the second insulator, is a tape-shaped insulator wound around,
An insulator containing mica or an insulator obtained by compositing nanoparticles or sub-nanoparticles, which has high insulation performance, is used for the wire insulation that is the first insulator, and the main insulator that is the second insulator is the first insulator. A rotary electric machine using an insulator containing a glass material whose insulating performance is lower than that of the insulator. In the rotary electric machine according to claim 1,
Let the insulation design electric field and thickness of the first insulator be a1 (V/m) and b1 (m), respectively, and the insulation design electric field and thickness of the second insulator be a2 (V/m) and b2 ( m), then
A rotary electric machine that satisfies the relationship a1×b1>a2×b2. In the rotary electric machine according to claim 1,
A rotary electric machine having a hardening material between insulated wires. In the rotary electric machine according to claim 1,
A rotating electrical machine in which adjacent insulated wires are in contact without providing a hardening material between the insulated wires. In the rotary electric machine according to claim 1,
A rotating electrical machine with a rated voltage of 1 kV or higher. In the rotary electric machine according to claim 1,
The rotating electrical machine is a motor for a vehicle. A rotating electric machine comprising a rotor and a stator, wherein the stator comprises a stator core and stator coils mounted in slots of the stator core,
In the stator coil, the surface of the wire conductor is coated with wire insulation to form an insulated wire, the insulated wire is wound and bundled to form a winding bundle, and the main insulation is provided around the wire bundle. and
The wire insulation is wound with mica tape having high insulation performance,
A rotary electric machine in which the main insulation is wound only with an inexpensive glass tape.

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