JPH0591686A - Insulating method of electric rotating machine and measuring device therefor - Google Patents

Abstract

PURPOSE:To realize a low cost insulating method in which partial discharge resistant characteristics can be enhanced by winding two enamel wires, treated with a solventless epoxy resin mixed with scalelike inorganic filler, a plurality of turns in parallel and providing four H-type take-out ports. CONSTITUTION:Two enamel wires, treated with a solventless resin mixed with scalelike inorganic filler, are wound a plurality of turns in parallel and H-type take-out ports are provided at four points. Coils 1, 2 are bundled with a thread 3 and two enamel wires of 1mm diameter are wound around the coils 1, 2 by five turns in parallel thus preparing a coil bundled at four points with the thread 3. Scalelike inorganic filler, i.e., mica powder, to be mixed with the solventless epoxy resin is made uniform and the average grain size thereof is varied. According to the invention, partial discharge resistance is enhanced and a low cost insulating method can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine stator coil insulation method and a measuring apparatus therefor.

2. Description of the Related Art The insulation of conventional small and medium-sized low-voltage rotating electric machines is
As shown in FIG. 3, a round wire enamel wire 4 is housed in a stator core 6 through a slot liner 5, treated with a solvent-type varnish or a solventless resin, and generally heat-cured, The insulation has many voids 7. Further, as these insulation tests, a twist pair method and a motorette method are generally used.

When operated by an inverter power supply, when the input power of the inverter is AC440V, the rectangular wave voltage E shown in FIG. 4 becomes about 600V.
The surge voltage e applied to the insulation is considered to be 1000 V or more, which is a voltage at which partial discharge is sufficiently generated. The carrier frequency that is the source of the rectangular wave voltage tends to be increased to 10 to 20 kHz due to the recent noise reduction, and it is expected that the life of the insulation system will be shortened when partial discharge occurs. In addition, the test method of the insulated wire was a complicated device.

[0002]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to provide a wire ring formed of an enamel electric wire inserted into a slot through a slot liner. A method of insulating a rotary electric machine, wherein a scale-like inorganic filler is mixed with a solventless epoxy resin in an insulating coil of a low-voltage rotary electric machine obtained by treating this with a solventless epoxy resin. As an example, a stator of a low-voltage rotating electric machine is treated with a mixture of 5 to 20 parts by weight of a scale-like inorganic filler of 150 to 2000 mesh with 100 parts by weight of a solvent-free epoxy resin to form a coating for an enamel wire. The thickness of the
It was found that the life is extended.

As the insulation tester, an enamel electric wire obtained by treating with a solventless epoxy resin mixed with a scale-like inorganic filler is wound two times in parallel,
The outlets are four H-shaped.

[0004]

[Function] By mixing a scale-like inorganic filler,
An inorganic mixed insulating layer with good partial discharge resistance is formed on the organic coating of the enamel electric wire, and the holding property of the impregnated resin is improved, and once impregnated resin does not easily flow while dripping during heat curing, As a result of filling the gaps between the enamel electric wires and between the enamel electric wires and the slot liner, the partial discharge inception voltage becomes high. In addition, fine cracks are less likely to occur due to the heating / cooling heat cycle. The test apparatus for the insulated wire will be described together with examples.

[0005]

Embodiments of the present invention will be described below with reference to the drawings and tables. 1 is an explanatory view showing an embodiment of claim 2 of the present invention, in which the enamel wire obtained in claim 1,
That is, two enameled electric wires obtained by treating with a solvent-free epoxy resin mixed with a scale-like inorganic filler are wound in parallel two or more times, and the take-out ports are set at four H-shaped positions and are bundled with a binding thread 3. Coil 1 and coil 2. As the coils 1 and 2, two enamel electric wires each having a wire diameter of 1 mm were wound in parallel 5 times and tied at 4 positions and tied with a thread 3. Examples 1, 2, and 3 are examples in which the number of parts of the mica powder as the scale-like inorganic filler mixed in the solventless epoxy resin is constant and the average particle size is changed. In Example 1, 10 parts by weight of mica powder having an average particle size of 2000 mesh (Nippon Mica Mfg. Co., Ltd .: A2000) was mixed with 100 parts by weight of a thermosetting type solventless epoxy resin, and the mixture was thoroughly stirred and then added to the coil. It was impregnated. Example 2 is a mica powder having an average particle size of 325 mesh (made by Nippon Mica Mfg. Co., Ltd .: A
10 parts by weight of 500) were mixed and the same treatment as in Example 1 was carried out. In Example 3, 10 parts by weight of mica powder having an average particle size of 150 mesh (Nippon Mica Mfg. Co., A100) was mixed with 100 parts by weight of a thermosetting solventless epoxy resin, and the same treatment as in Example 1 was performed. did. With the above coil,
Table 1 shows a comparison of characteristics with a coil treated only with a conventional thermosetting type solventless epoxy resin.

[0006]

[Table 1]

Table 1 shows partial discharge inception voltage (Vi) and extinction voltage (Ve) between two lines at 160 kHz at 10 kHz.
Are compared. In Examples 1, 2 and 3, the partial discharge inception voltage (Vi) and the extinction voltage (V
e) is also expensive. As a comparison between Example 1, Example 2 and Example 3 in which the average particle size of mica was changed, Example 2 showed a slight excellent property. Figure 2 also shows that at 160 ° C
With the same formulation as above, the breakdown time when applying 10 kHz and 1000 V (peak value) is compared. In Examples 1, 2 and 3, no cracks or cracks were formed in the resin in any of the coils. Although it did not break even in time, the comparative example in which mica powder was not mixed did break in an average of 1.2 hours even if no cracks or cracks were formed. Examples 4 and 5 are examples in which the average particle size of the mica powder mixed in the solventless epoxy resin is kept constant and the number of mixed parts is changed. In Example 4, 20 parts by weight of mica powder having an average particle size of 2000 mesh (manufactured by Mica Japan Co., Ltd .: A2000) was mixed with 100 parts by weight of the thermosetting solventless epoxy resin, and in Example 5, the same mesh was used. The same treatment as in Example 1 was performed on the above-mentioned coil using mica powder mixed in 5 parts by weight. Table 2 shows the results of the partial discharge inception voltage (Vi) and the extinction voltage (Ve) measured under the same conditions as in Table 1.

[0008]

[Table 2]

The characteristics of Table 2 are Vi, V from the comparative example of Table 1.
Both e are high, and there is no significant difference from the 10 parts by weight of Example 1.
Moreover, the voltage was applied under the same conditions as in FIG. 2, but it was not broken after 1000 hours. Even if the mesh of mica powder was changed to 325 or 150 and the number of mixed parts was changed as in Examples 4 and 5, there was no big difference. If 20 parts by weight or more of mica powder is mixed, the viscosity of the resin increases and the amount of resin adhering increases, but impregnation property deteriorates and it becomes difficult to fill the voids between the enamel electric wires. If it is 5 parts by weight or less, the effect of the mica powder becomes difficult to be obtained. If the average particle size of mica is larger than 150 mesh, it will not be sufficiently impregnated between the enamel electric wires, and if the average particle size of mica is smaller than 2000 mesh, the viscosity of the resin mixed with mica powder will increase and the workability will be poor. Become. In the examples, a thermosetting solventless epoxy resin was used as the solventless epoxy resin, and mica powder was selected as the scale-like inorganic filler, but the invention is not limited to these, and an epoxy resin that cures by ultraviolet rays, kaolin, etc. The same effect can be obtained with the powder of the inorganic filler.

[0010]

As described above, according to the present invention,
Mixing an appropriate amount of mica powder with a suitable average particle size in a solventless epoxy resin creates an inorganic layer on the coating of the enamel wire,
In addition to improving partial discharge resistance, the resin layer also contains mica powder, which makes it resistant to heat cycles for heating and cooling, and is particularly resistant to surge voltage due to the cable constant of the inverter power supply. Since it is not necessary to reinforce the tape or the like, it is possible to provide an insulating method that can be sufficiently dealt with at low cost.

[0010]

[Brief description of drawings]

FIG. 1 is an outline drawing of a coil used for comparison of characteristics.

[FIG. 2] FIG. 2 is a life characteristic diagram for comparison with and without the inclusion of mica powder.

FIG. 3 is a sectional view of a stator slot of a general low-voltage rotating electric machine.

FIG. 4 is a waveform diagram illustrating a resonance phenomenon caused by a cable.

[0011]

[Explanation of symbols]

 1 coil 2 coil 3 binding thread 4 enamel electric wire 5 slot liner 6 stator core 7 void

Claims (2)

[Claims] 1. A wire ring formed of an enamel electric wire inserted into a slot through a slot liner, and an insulating wire ring of a low-voltage rotating electric machine obtained by treating the wire with a solventless epoxy resin, wherein the solventless epoxy is used. A method of insulating a rotating electric machine, which comprises mixing a scale-like inorganic filler into a resin, and a measuring device therefor. 2. An enamel electric wire obtained by treating with a solvent-free epoxy resin mixed with a scale-like inorganic filler is wound in parallel two times, and its take-out ports are four H-shaped points. A method for insulating a rotating electric machine and its measuring device.