JPH04108352U - Structure of insulation part of rotating electrical machine winding - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent resin leakage from insulating parts in a fully impregnated type of rotating electric machine winding. [Structure] The coil end first layer insulation 5 is made of adhesive-dissolved material, and the lead wire branch part is made of swelling mica compound 6 that fills the gap, and is used as external insulation without impairing the impregnability and has a curing accelerator. Tape 8 had the following characteristics.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to the insulation coating of rotating electric machine windings, and is insulated using a total impregnation method. This invention relates to the structure of the insulating part of the coil.

0002

[Conventional technology and its issues]

One of the methods for insulating the coils of rotating electric machines is called the total impregnation method. In this method, an insulated straight section of the coil is installed in the core slot, and then the core is connected. This is a method in which resin is impregnated and hardened under vacuum pressure, and the iron core and coil are integrated into a dense structure. Features include an insulating layer and excellent mechanical, electrical, and environmental resistance properties. There is. However, on the other hand, there is the problem of resin processing costs, and this processing cost is , depends on the pot life of the resin. In other words, the pot life is long and The more times it is used, the cheaper the processing cost per unit, so it is no longer necessary to heat it. It has a low viscosity that allows it to be impregnated even when heated (warming shortens the pot life). Research has been conducted into resins with a long pot life, and some of them have been put into practical use.

0003 However, in this way, we were able to extend the pot life of the resin and reduce processing costs. However, if the above resin is used, the viscosity will further decrease during the resin curing process. impregnated wood due to the fact that the longer the pot life, the longer the gelation time. There is a problem with fat leakage. Moreover, if the impregnated resin leaks out, there will be a void in the insulation. This often results in the formation of cracks and voids, leading to partial discharge deterioration and a decrease in mechanical strength. Are known.

0004 Therefore, in order to prevent the resin from flowing out, it is currently necessary to rotate the processed material during curing. The method used is to roll it over and seal it to prevent the resin from leaking out. death However, there are problems with the safety and efficiency of using the drying oven, and with the method of However, there is a problem in that the stronger the seal, the worse the impregnability. Therefore, hard There is a need for an insulation method that does not require rotating the object to be treated during oxidation and does not impair impregnability. ing.

[0005] In order to achieve the goal of improving impregnation without resin leakage, it is necessary to It is important to clarify the outflow mechanism of the high voltage stator coil. consider the rules. That is, in the hexagonal coil 1 shown in FIG. The output is mostly in the direction of penetration of the insulation layer at the coil straight section 1a in the core slot. Most of the wires pass through the gaps between the strands 2 and the gaps between the strands 2 and the ground insulating layer 3. is guided to the coil end part 1b, and the gap at the branch part of the lead wire 4 and the coil It was found that the leakage mainly occurred from the part of the head of the head part 1b where the insulation was sparse. I made it clear. Moreover, the coil attached to the stator core is The position of the lower coil straight part (side) is changed from horizontal to vertical. It was also found that the amount of resin flowing out increases as the condition increases.

[0006] Based on the above leakage mechanism, we reconsidered the resin leakage prevention method and (a) A method to speed up the curing time and reduce the amount of spillage, and (b) a sealing method that does not impair impregnability. I considered it. Among these, method (a) involves mixing a curing accelerator into the impregnated resin. Another method is to apply a curing accelerator to the insulating tape. However, the former is impregnated wood This shortens the pot life of the fat and increases costs. Therefore, in the latter condition The first method is to apply a curing accelerator to a certain insulating tape.

[0007] Next, we also investigated the sealing method described in (b) above that does not impair the impregnation properties.

[0008]

[Means to solve the problem]

Examination of insulating tape coated with curing accelerator and inspection of seals that do not impair impregnability. As a result of the discussion, the present invention has the following structure. In other words, the coil insulation at the coil end Wrap semi-cure insulating tape around the first layer of the In some cases, the lead wire insulation is sandwiched between the lead wire insulation and the coil insulation, and the lead wire insulation is and a swellable mica filling compound wound to envelop the coil insulation; Wrap the above coil insulation in an overlapping manner with mica tape containing a curing accelerator. It is characterized by having a side part insulation.

[0009]

[Effect]

First, when considering applying a curing accelerator to an insulating tape, the following conditions must be met in this case. a. Reacts with impregnating resin at low temperature. stomach. The adhesive in the insulating tape will not react with the adhesive during storage and lose the flexibility needed for work. cormorant. It does not elute into the impregnating resin and does not affect the pot life of the impregnating resin. workman. Does not adversely affect insulation properties. Based on the above conditions, we evaluated the storage stability of mica tape, reactivity with the impregnated resin, influence on the pot life of the impregnated resin, and tan δ ₀ for four types of curing accelerators, and the results shown in Table 1 were obtained. It came out. In Table 1, ◯ indicates good, Δ indicates fair, and × indicates poor.

0010

[Table 1]

[0011] As a result, it was found that a metal zinc-based accelerator was most suitable.

0012 In addition, when devising a sealing method that does not impair impregnating properties, a gap must be ensured during impregnation. It becomes a conductive path for the impregnated resin, but it must not be immersed in the resin for a long time (5 hours or more). The tape swells to fill gaps and dissolves the adhesive, creating a highly viscous layer between the tape layers. We focused on semi-cured materials that form a resin film and prevent impregnated resin from passing through. . As a result of our study, we found that areas with large gaps, such as branching parts of lead wires, have a high degree of swelling (more than twice as large). Above), using a mica-filled compound sheet (mica filling amount 65% to 55%) For areas where the insulation tape tends to be sparse, such as the head of the coil end, the swelling property is Although it is small (1.2 to 1.5 times), the adhesive dissolves and forms a highly viscous resin film. The purpose can be achieved by wrapping semi-cured insulating tape. found.

[0013] Results of the above consideration Wrap mica tape containing metal zinc curing accelerator on ground insulation. Wrap semi-cured insulation tape around the coil end insulation as the first layer. Wrap a swellable mica-filled compound sheet around the outlet wire branch of the coil end. wear We have established a technology that prevents the impregnated resin from flowing out during curing through a combination of the following.

[0014]

【Example】

An embodiment of the present invention will now be described with reference to FIG. Figure 1 shows the structure However, the explanation will be given in the order of the manufacturing process. A round wire with a wire size of 2.0 mm is self-fused onto the polyester enamel. Two strands of wire 2 coated with a synthetic coating film are wound in 4 rows and 10 layers. The coil was molded into a hexagonal full coil with a straight portion 1a having a length of 450 mm. After applying the insulation 4a of the lead wire 4, as shown in FIG. Semi-cure mica tape 5 was wound once in a half wrap around the first layer. Specifically, this semi-cured mica (insulating) tape 5 is made of glass fiber, polyester Single base materials such as fibers, heat-resistant films, etc., or composites made by bonding mica to these base materials. An example is one in which the combined material is impregnated with an adhesive resin and cured to a B-stage state. 10 to 20 mm on the part of the lead wire branching part 4b where the lead wire insulation 4a is applied. Swellable mica filled concrete with a thickness of 0.8 mm and a width of 50 mm so as to overlap. The pound sheet 6 is sandwiched between the lead wires 4 and wound once. This swellable mica-filled compound sheet 6 is made of mica powder and resin compound. A B-stage sheet made of It is something. The coil end part 1b is lined with ordinary dry type glass as its insulation 7. Wrap the laminated mica tape twice in a half wrap. As the linear part insulation 8, we used a gas containing a curing accelerator (zinc naphthenate) in the adhesive. Lath-backed laminated mica tape (0.15t x 25 width) is used as coil end insulation 7. , wrap it 4 times in half-wrap so that it overlaps, and then apply the specified outer insulation on top of it. Edged. Attach an aluminum model slot to the core slot insertion part and insert an epoxy-based The impregnated resin was subjected to vacuum pressure impregnation (VPI) treatment. The upper coil straight section and the lower coil are the conditions where resin is most likely to flow out during curing. The coil was set in a drying oven so that the straight part was vertical and hardened by heating.

[0015] As a result, the semi-cured mica tape 5 is applied to the first layer of the coil end portion 1b. , the adhesive melts and forms a highly viscous resin film, which is applied to the coil end lead wire branch. A mica-filled compound sheet, which swells when immersed, is applied to fill the gaps. The ground insulation of the straight section insulation 8 leading to the end portion 1b contains no metal zinc hardening accelerator. Accelerate curing of the resin with edge tape.

[0016] (Comparative Example I) In the example, mica tape without a curing accelerator was used as the linear section insulation 8. (Comparative example II) In the example, the swellable mica-filled compound sheet 6 of the lead line branching part 4b was excluded. there was. (Comparative Example III) In the example, the semi-cured mica tape 5 of the coil end portion 1b was excluded. As an evaluation of the resin leakage prevention of the above insulation method, the coil size that is on the upper side during curing is The tan δ-voltage characteristics were measured separately for the coil side portion and the lower coil side portion. table Figure 2 shows the Δtan δ characteristics at the rated voltage.

[0017]

[Table 2]

[0018] In the example, Δtan δ on the upper side and lower side are almost the same and small, so almost no It can be seen that there is no resin leakage. In the case of Comparative Example I, Δtan δ is almost the same for both the upper and lower coils, but Δtan Since both values of δ were large, outflow from the coil end portion 1b was suppressed. However, due to the slow curing speed, outflow occurred through the layer direction. implementation In the case of Example II and Example III, Δtan δ of the upper coil is large, and the coil The resin flows through the lead wire branch part 4b of the end part 1b and the gap in the end part insulation. I can see that there was a leak.

[0019] As can be seen from the above results, the total impregnation method is effective in reducing resin outflow during curing. In order to prevent this problem, the following embodiment configuration is required. Semi-cure insulation tape is applied to the first insulation layer of the coil end portion 1b. As a treatment for the gap in the lead wire branch part 4b, lead wire insulation and coil insulation are used. A lubricating mica-filled compound seal is applied between the lead wire insulation and the coil insulation. to apply Insulate the straight section all the way to the end of the coil using mica tape containing an accelerator. and.

[0020]

[Effect of the idea]

As explained above, depending on the location, the hardening agent is placed or swollen. This makes it possible to sufficiently impregnate the impregnating resin and prevent its outflow. child As a result, a method to prevent resin from flowing out during curing was established, resulting in low viscosity and high resistance to gelation. It becomes possible to apply impregnating resin with a slow pot life (long pot life), reducing insulation processing costs. can be significantly lowered, eliminating the need to rotate the workpiece during curing, and reducing installation costs. Reduces equipment costs, improves safety, and improves curing processing capacity. As a result, there are no restrictions on the location of As a result, it became possible to reduce the insulation thickness, leading to smaller and lighter equipment.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view of the vicinity of the lead line of a coil showing the structure of an embodiment.

FIG. 2 is a conceptual diagram of a resin outflow path.

[Explanation of symbols]

1a Straight section 1b Coil end part 4 Exit line 4a Lead wire insulation 4b Output line branch 5 Semi-cure insulation tape 6 Swellable mica-filled compound sheet 7 Coil end insulation 8 Straight section insulation

Claims (1)

[Scope of utility model registration request] Claim 1: A semi-cure insulating tape is wound around the first layer of coil insulation at the coil end, and at the lead wire branch part of the coil end, a semi-cure insulation tape is wound between the lead wire insulation and the coil insulation. A swellable mica-filled compound is sandwiched and wound so as to wrap around the lead wire insulation and the coil insulation, and a side insulation is formed by wrapping and wrapping a mica tape containing a curing accelerator on the coil insulation. A structure of an insulating part of a rotating electric machine winding.