KR20170101421A - Rectangular winding wire having corona resistance - Google Patents

Abstract

The present invention relates to a rectangular winding with corona resistance, and more particularly, to a rectangular winding with corona resistance, capable of obtaining not only excellent corona resistance but also an excellent insulation characteristic by including an insulation film with excellent flexibility and excellent adhesion between a conductor and an insulation layer.

Description

Rectangular winding wire having corona resistance < RTI ID = 0.0 >

The present invention relates to an inner corona gono winding. Specifically, the present invention relates to an inner corona-type flat rectangular winding having an insulating film excellent in the resistance to corona resistance, excellent in adhesion between the conductor and the insulating layer, and excellent in flexibility and having excellent insulation characteristics.

An insulated winding means a covered insulated wire wound on an electronic device such as a transformer. Here, the conductor of the insulated winding is mainly made of copper or aluminum having a high conductivity, and a flat type is used for a large-sized electric apparatus. The insulated winding to which such a flat conductor is applied is called a square winding or a square insulation winding do. On the other hand, the insulation type was initially wound with an insulating tape or a thread, but the enamel line rapidly increased with the development of the chemical industry.

The enamel wire means a wire made by repeatedly putting an insulating enamel on the surface of a copper wire and heating it to a high temperature. The enameled wire is advantageous in that it has a thin film, high insulating property, excellent thermal stability, and is not easily denatured to chemical agents. Therefore, the enameled wire is widely used mainly for making electromagnetic force, and is widely used as a winding of a transformer and a motor, which are electric devices using electromagnetic force. The enameled wire may be a formal wire, a polyurethane wire, a polyester wire, a heat-resistant synthetic enamel wire, or a planetary enamel wire, depending on the material of the enamel.

When the insulated winding including the enameled wire is applied to a motor in a high voltage environment, if there is insufficient inner corona characteristics, a minute gap is formed between the insulating coating and the insulating coating or a small gap is formed in the insulating coating, And collisions of the charged particles generated by the corona discharge cause heat generation and decomposition of the insulating coating, resulting in dielectric breakdown.

In recent years, a system using an inverter motor or the like has been utilized due to energy saving. The inverter is a variable variable speed control device of a metabolism, which is capable of varying the speed of a motor. The inverter is switched from several kHz to several tens of kHz to generate a noise-free sinusoidal wave, thereby generating an inverter surge voltage which is twice as high as the inverter output voltage, resulting in insulation breakdown of the electrical equipment square winding It is also known that the dielectric breakdown caused by the inverter surge is caused by the overvoltage caused by the inverter surge causing the corona discharge.

Enameled wires in which inorganic insulating particles such as silica and titanium dioxide are added to an insulating coating resin in order to impart sufficient corona resistance to such insulating windings are known. The inorganic insulating particles contribute not only to imparting corona resistance to the enamel wire but also to improve thermal conductivity, decrease thermal expansion and increase strength.

However, as the content of the inorganic insulating particles increases, the inner corona characteristics are improved, but the adhesion between the conductor and the coating film and the flexibility of the coating film are deteriorated. Therefore, when a winding containing a large amount of inorganic insulating particles in an insulating coating is applied to an electric appliance, a large number of cracks are generated in the insulating coating, and as a result, the effect of the corona resistance of the original purpose can not be exhibited. The more insulating particles are present in the insulating coating adjacent to the conductor, the more pronounced.

Therefore, there is a strong demand for an inner corona insulating winding having an insulating film excellent in the resistance to corona resistance, excellent in adhesion between the conductor and the insulating layer, and excellent in flexibility and having excellent insulation characteristics.

An object of the present invention is to provide an inner corona-type flat rectangular winding having an insulating film excellent in the resistance to corona resistance.

It is another object of the present invention to provide an inner corona-type flat rectangular winding having an insulating film excellent in adhesion between a conductor and an insulating layer and flexibility.

It is another object of the present invention to provide an inner corona-type flat rectangular winding having excellent insulation characteristics.

In order to solve the above problems,

A square winding comprising a flat conductor and an insulating layer surrounding the flat conductor, wherein the insulating layer comprises a first insulating layer in contact with the square conductor and a second insulating layer surrounding the first insulating layer, The insulating layer comprises a polymeric resin and inorganic particles dispersed in the resin, wherein the thickness of the second insulating layer is 5 to 40 占 퐉.

Wherein the insulating layer has a thickness of 70 to 120 占 퐉.

Further, the present invention provides an inner corona-type flat rectangular winding which is characterized in that the edge coverage defined by Equation (1) is 100 to 150%.

[Equation 1]

Edge Coverage = {average insulation thickness at the corners of the square winding / average insulation thickness of the flat plane winding} 100

Here, the resin composition forming the insulating layer has a viscosity of 5 to 40 poise and a surface tension of 10 to 50 dyn / cm 2.

On the other hand, the polymer resin contained in the second insulating layer may be a polyvinyl formal resin, a polyurethane resin, a heat resistant polyurethane resin, a polyester resin, a polyester imide resin, a polyamide imide resin, Amide resin, and the content of the inorganic particles dispersed in the resin is 10 to 20% by weight based on the total weight of the second insulating layer. Provide a square winding.

The inorganic particles may be at least one selected from the group consisting of silica, zeolite, alumina, titanium dioxide, zirconia, yttria, mica, clay, chromium oxide, zinc oxide, iron oxide, magnesium oxide, calcium oxide, scandium oxide, And the size of the inorganic particles is 40 nm or less.

The insulating layer further includes a third insulating layer surrounding the second insulating layer, and the third insulating layer includes a self-lubricating resin.

Here, an inner corona-like flat rectangular winding is characterized in that the self-lubricating resin is a self-lubricating polyamide imide.

On the other hand, the first insulating layer may be formed from a group consisting of a polyvinylformal resin, a polyurethane resin, a heat resistant polyurethane resin, a polyester resin, a polyester imide resin, a polyamide imide resin, a polyimide resin and a polyamide resin And one or more adhesion members selected from the group consisting of a melamine based adhesive agent, an amine based adhesion agent, a mercaptan based adhesion agent and a polycarbodiimide adhesion agent based on 100 parts by weight of the polymer resin, And 3 parts by weight of a polyimide resin.

Corrosion resistance of the corona coil according to the present invention exhibits an excellent effect of improving the inner corona resistance of the insulating layer by adding specific inorganic particles to the insulating layer forming the specific insulating layer and the insulating layer.

In addition, the corona-coherent square-wave winding according to the present invention exhibits an excellent effect of enhancing the adhesion between the conductor and the insulating layer and the flexibility, even though the corona resistance is improved by adding specific inorganic particles to the insulating coating forming the insulating layer.

In addition, the corrugated sagittal coil winding according to the present invention exhibits an excellent insulating characteristic of the insulating layer by partially varying the thickness of the insulating layer.

1 schematically shows a cross-sectional structure of an inner corona-type flat rectangular winding according to the present invention.
Fig. 2 shows a reference drawing for calculating edge coverage, which is a ratio of flat to edge film thickness in an inner corona-type square-shaped winding according to the present invention.
Fig. 3 schematically shows a cross-section of an inner corona-type square-wave winding with an edge coverage of 111%.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Like reference numerals designate like elements throughout the specification.

1 schematically shows a cross-sectional structure of an inner corona-type flat rectangular winding according to the present invention.

As shown in FIG. 1, an inner corona-type flat rectangular winding according to the present invention includes a flat type conductor 10 and an insulating layer 20 surrounding the conductor 10, and the insulating layer 20 Has a first insulating layer 21 having an excellent adhesion to the conductor 10 and contacting the conductor 10 and a second insulating layer 22 surrounding the first insulating layer 21 and having excellent corona resistance, And may further comprise a third insulating layer 23 at the outermost periphery that implements the smooth surface of the square winding according to the present invention and surrounds the second insulating layer 22.

The conductor 10 is mainly made of a copper or aluminum material having a high electrical conductivity, and may preferably be made of a copper material. In addition, the insulating layer 20 may be generally formed of a polymer resin or the like, which will be described later.

The thickness of the conductor 10 and the insulating layer 20 may conform to the KS standard (KS No. KS C 3107) and the standard thickness of the insulating layer 20, that is, the maximum thickness of the insulating layer 20 The minimum thickness increases together with the cross-sectional area of the conductor 10, for example, it may be 70 to 120 탆.

Partial Discharge Inception Voltage (PDIV) can be easily exposed to a partial discharge at a level of 900 peak voltage (Vp) when the thickness of the insulating layer 20 is less than 70 탆, There is a problem in that when the insulating layer 20 is formed with poor appearance, the solvent remains in the inside of the insulating layer 20 when the solvent is volatilized after the solid portion is adhered to the surface of the conductor 10 and the heat resistance of the insulating layer 20 is lowered .

The polymeric resin forming the insulating layer 20 may be a polyvinyl formal resin, a polyurethane resin, a heat-resistant polyurethane resin, a polyester resin, a polyester imide resin, a polyamideimide resin, a polyimide resin, May be used.

Specifically, the first insulation layer 21 of the insulation layer 20 may be made of a polyester resin or the like having excellent film flexibility and adhesion to a conductor, and the second insulation layer 22 is somewhat insufficient in flexibility A polyester imide, a polyimide resin and the like, which are excellent in heat resistance, mechanical strength and the like. Thus, the square winding according to the present invention can simultaneously satisfy the flexibility of the winding, the adhesion between the conductor 10 and the insulating layer 20, and the mechanical strength of the winding at the time of bending.

The first insulation layer 21 may further include an adhesion enhancing agent so that the corona resistance can be effectively exhibited by further enhancing the adhesion with the conductor 10. The adhesion-promoting agent may be selected from melamine-based compounds such as alkoxy melamine resins such as butoxy, amine-based ones such as trialkylamine, mercaptans such as mercaptobenzimidazole, and polycarbodiimide. The content of the adhesive agent may be 1 to 3 parts by weight based on 100 parts by weight of the resin constituting the first insulating layer 21. [

The corrugated inner corona coil according to the present invention can effectively impart the corona resistance to the rectangular winding by including the inorganic particles in the second insulating layer 22 of the insulating layer 20. Wherein the inorganic particles are at least one inorganic particle selected from silica, zeolite, alumina, titanium dioxide, zirconia, yttria, mica, clay, chromium oxide, zinc oxide, iron oxide, magnesium oxide, calcium oxide, scandium oxide, And preferably 40 nm or less.

Methods for producing the resin in which the inorganic particles are dispersed are well known and include, for example, the ball-milling disclosed in U.S. Patent No. 6,403,890, the high shear mixing disclosed in U.S. Patent No. 4,493,873 a simple stirring method disclosed in U.S. Patent No. 6,180,888, a sol-gel method disclosed in JP-A-2003-36731, and the like can be used.

In order to effectively exhibit the corona resistance, the inorganic particles preferably have excellent dispersion characteristics, a very fine particle size, a nanoparticle of 4 to 100 nm, more preferably 40 nm or less, a high specific surface area (BET) Preferably, 100 to 300 m < 2 > / g, high purity, preferably 95% or more, spherical particle shape, pore member and the like are required, and various methods for improving these properties are already known.

For example, German Patent No. 4209964 discloses an inorganic particle surface-modified for easy dispersion in a resin, for example, a surface-silanized inorganic particle. Specifically, the surface-silane inorganic particles are prepared by adding the inorganic particles to a solvent such as toluene, xylene, ethanol, or cresol to prepare a mixed solution, adding an amine silane, a phenyl silane, an aniline silane, And then adding a silane compound such as silane having a functional group to the reaction mixture.

In the present invention, the content of the inorganic particles may be 10 to 20% by weight based on the total solid weight of the second insulating layer. When the content of the inorganic particles is less than 10% by weight, the corona resistance is insufficient. When the content of the inorganic particles is more than 20% by weight, the adhesion between the first insulating layer 21 or the third insulating layer 23 and the second insulating layer 22 , The flexibility of the insulating layer 20, and the like may be deteriorated.

Furthermore, the thickness of the second insulating layer 22 in which the inorganic particles are dispersed may be 5 to 40 탆. If the thickness of the second insulating layer 22 is less than 5 탆, the duration of the partial discharge may be insufficient for less than 2 hours, while if it exceeds 40 탆, the insulating layer 20 ) Can be destroyed.

The corona-resistant brass coil according to the present invention is characterized in that the inorganic particles for embodying the corona resistance are included in the second insulation layer 22, thereby improving the adhesion between the first insulation layer 21 containing no inorganic particles and the conductor 10 So that it is possible to maintain excellent corona resistance even when winding and bending of the square winding.

The corona-coherent sinusoidal winding according to the present invention may further include a third insulating layer 23 made of a self-lubricating resin at its outermost portion in order to realize its smooth surface. The self-lubricating property means a property that the frictional resistance is small even when the lubricant is not supplied, that is, the surface is smooth, and the self-lubricating resin can be produced by introducing a self-lubricating functional group into the polymer main chain.

For example, trimellitic anhydride, aromatic diisocyanate and aminosiloxane are polymerized in a certain equivalent ratio to obtain a polyamide carbamate as an intermediate, followed by imidization and an aromatic hydrocarbon-based solvent for viscosity control, A lubricating polyamide imide can be produced. On the other hand, the outermost layer 24 may be formed by further adding a magnetic lubricant such as ethylene or graphite to a resin such as polyamide imide. Here, the content of the magnetic lubricant may be 1 to 10 parts by weight based on 100 parts by weight of the resin.

Fig. 2 shows a reference drawing for calculating edge coverage, which is a ratio of flat to edge film thickness in an inner corona-type square-shaped winding according to the present invention.

2, the corona-coherent sinusoidal winding according to the present invention may have four planes f1, f2, f3, f4 and four corners r1, r2, r3, r4, R2, r3 and r4 portions are formed to be thin by the surface tension of the insulating coating at the time of forming the insulating layer 20, and the insulating layer 20 (r1, r2, r3 and r4) Can be greatly reduced.

The corona coiled square winding according to the present invention may have an edge coverage of 100 to 150% defined by Equation 1 below. The square winding has an edge coverage of 100 to 150%, so that it is possible to suppress deterioration of the insulation characteristic of the insulating layer 20 by the corner portion. For example, the cross section of a square winding with an edge coverage of 111% is as shown in Fig.

[Equation 1]

Edge coverage = {average insulation thickness of edge (r1, r2, r3, r4) / average insulation thickness of plane (f1, f2, f3, f4)

The edge coverage adjusts the viscosity of the resin composition forming the insulating layer 20 to 5 to 40 poise and the surface tension to 10 to 50 dyn / By using a coating die having a radius.

[Example]

1. Manufacturing Example

A square winding or an annular winding specimen was fabricated with the configuration shown in Table 1 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Square conductor
(Length (mm) x width (mm)) or
Annular conductor (diameter (mm)) 1.3 x 2.5 2.2 x 3.3 2.2 x 3.3 2.2 x 3.3 Φ1.2 0.9 x 1.5 Corner radius (mm) 0.4 0.5 0.5 0.5 - 0.3 Insulation layer thickness (탆) 80 82 72 85 35 45 Thickness of first insulating layer (占 퐉) 25 25 25 20 20 20 Thickness of the second insulating layer (占 퐉) 20 35 3 47 12 - Thickness of the third insulating layer (占 퐉) 35 22 44 18 3 25

- first insulating layer: polyamide-imide resin

- Second insulating layer: polyamideimide resin + zeolite

- Third insulating layer: polyamide-imide resin

2. Property evaluation

1) Bending test

When each of the insulating winding specimens prepared in the examples and the comparative examples is bent at a specific radius, whether or not cracks exist in each specimen is recorded.

2) Evaluation of adhesion

The insulating winding specimens prepared in the examples and comparative examples were quickly stretched and stretched to 20%. Record the presence of cracks in each specimen after elongation.

3) Evaluation of partial discharge start voltage

Partial discharge initiation voltages were measured on the insulating winding specimens produced in Examples and Comparative Examples, respectively. It is preferable that the peak voltage is 1200 Vp or more.

4) Evaluation of corona resistance

A specimen twisted in two rows was prepared by applying a constant load and twist specified at one end of each pair of insulating winding specimens prepared in the examples and comparative examples, and a voltage having a sinusoidal frequency of 10 kHz and a frequency of 10 kHz was applied to both ends of the sample To record the pulse endurance time. And the pulse endurance time to the time when the short circuit occurs is more than 2 hours.

The evaluation results of the physical properties are shown in Table 2 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Bending test Crack × Crack × Crack × crack - Crack × Adhesion evaluation - - - - Crack × - Partial discharge
The start voltage (Vp) 1200 1240 1170 1300 810 870 My Corona Castle 10 hours
More than 10 hours
More than 2 hours
under 10 hours
More than 7 hours
under Less than 20 minutes

As shown in Table 2, it was confirmed that the square winding of the example according to the present invention is excellent in flexibility, adhesion between conductor and insulating layer, and corona resistance.

On the other hand, in the rectangular winding of Comparative Example 1, the thickness of the second insulating layer was excessively thin and the square winding of Comparative Example 4 had no second insulating layer, so that the corona resistance was greatly lowered. It was confirmed that a crack occurred in the insulating layer when the thickness of the second insulating layer was excessively bent and that the cyclic winding of Comparative Example 3 had a low partial discharge starting voltage and a poor adhesion between the conductor and the insulating layer.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. . It is therefore to be understood that the modified embodiments are included in the technical scope of the present invention if they basically include elements of the claims of the present invention.

10: conductor 20: insulating layer

Claims (9)

A square winding comprising a flat conductor and an insulating layer surrounding the flat conductor,
Wherein the insulating layer includes a first insulating layer in contact with the rectangular conductor and a second insulating layer surrounding the first insulating layer,
Wherein the second insulating layer comprises a polymer resin and inorganic particles dispersed in the resin,
Wherein the thickness of the second insulating layer is 5 to 40 占 퐉. The method according to claim 1,
Wherein the insulating layer has a thickness of 70 to 120 占 퐉. 3. The method according to claim 1 or 2,
Wherein the edge coverage defined by Equation (1) below is 100 to 150%.
[Equation 1]
Edge Coverage = {average insulation thickness at the corners of the square winding / average insulation thickness of the flat plane winding} 100 The method of claim 3,
Wherein the resin composition forming the insulating layer has a viscosity of 5 to 40 poise and a surface tension of 10 to 50 dyn / cm < 2 >. 3. The method according to claim 1 or 2,
Wherein the polymer resin contained in the second insulating layer is at least one selected from the group consisting of a polyvinylformal resin, a polyurethane resin, a heat resistant polyurethane resin, a polyester resin, a polyester imide resin, a polyamide imide resin, a polyimide resin and a polyamide resin And at least one resin selected from the group consisting of < RTI ID = 0.0 >
Wherein the content of the inorganic particles dispersed in the resin is 10 to 20% by weight based on the total weight of the second insulating layer. 3. The method according to claim 1 or 2,
Wherein the inorganic particles are at least one selected from the group consisting of silica, zeolite, alumina, titanium dioxide, zirconia, yttria, mica, clay, chromium oxide, zinc oxide, iron oxide, magnesium oxide, calcium oxide, scandium oxide,
Wherein the inorganic particles have a size of 40 nm or less. 3. The method according to claim 1 or 2,
Wherein the insulating layer further comprises a third insulating layer surrounding the second insulating layer,
Wherein the third insulating layer comprises a self-lubricating resin. 8. The method of claim 7,
Wherein the self-lubricating resin is a self-lubricating polyamide imide. 3. The method according to claim 1 or 2,
Wherein the first insulating layer is selected from the group consisting of a polyvinyl formal resin, a polyurethane resin, a heat resistant polyurethane resin, a polyester resin, a polyester imide resin, a polyamide imide resin, a polyimide resin and a polyamide resin One or more polymeric resins, and
And 1 to 3 parts by weight of at least one adhesive agent selected from the group consisting of a melamine-based adhesive agent, an amine-based adhesive agent, a mercaptan-based adhesive agent and a polycarbodiimide-based adhesive agent based on 100 parts by weight of the polymer resin To my corona, the castle of the castle is reeled.

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