JPH0217840A - Coil insulating layer for high voltage rotary electric machine - Google Patents

Abstract

PURPOSE:To prevent a defect due to the flowout of resin by coating and impregnating the main insulating base material layer of a lumped mica foil with curing promotor in which tertiary amine and metal complex are mixed as an insulating tape, lap winding the tape on a shaped coil conductor, impregnating it with resin and heat-treating it. CONSTITUTION:An insulating tape 11 is formed as a laminate of a reinforcing layer 12 made of polyimide film, a main insulating base material layer 13 made of a lumped mica foil, and a binder 14 for bonding both. As a promotor 16 to be coated and impregnated at the layer 13 a mixture of tertiary amine and metal complex is employed. The tape 11 is semilap wound closely on a shaped coil conductor 7 to form an insulating base material layer 15. As resin 18 to be impregnated thermosetting epoxy resin or the like is, for example, vacuum impregnated and thermoset.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coil insulating layer of a high-voltage rotating electric machine, and particularly to the structure of an insulating tape thereof.

[Conventional technology]

In high-voltage rotating electrical machines, increasing the heat resistance of the coil insulating layer increases the allowable temperature rise of the coil conductor, and by forming the insulating layer thinner, the cross-sectional area of the coil is reduced, making the 2-rotating electrical machine smaller and lighter. Therefore, coil insulation RR is required to have various performances such as electric field resistance, heat resistance, good thermal conductivity, and thermal stress resistance.

By the way, FIG. 4 is an enlarged view of a main part showing an example of a conventional coil insulating layer. In the figure, 1 is an insulating tape,
The main insulating base material layer 3 made of laminated mica foil is attached to the reinforcing material 2 using a binder 4, and the insulating tape 1 having a hardness suitable for the usage conditions is closely covered with the surface of the shaped coil conductor 7 and half overlapped. to form an insulating base material NA5 consisting of a plurality of insulating tape layers 5A, 5B, etc., and impregnated with a low viscosity impregnated resin 8 made of, for example, an epoxy resin under vacuum pressure, and then harden the impregnated resin. The coil insulating layer is formed by heating and curing at a predetermined temperature.

However, the curing time for the binder 4 and the impregnated resin 8 is long, and the adhesion of the insulating tape tends to be uneven, especially at the coil bends. As the viscosity of the resin decreases, it becomes easier to flow, and then the impregnating resin and binder 4
As the reaction progresses, the viscosity increases and it becomes impossible to flow. After a longer period of time, it completely hardens.

[Problem to be solved by the invention]

As mentioned above, because the reaction is slow, it takes a long time for the impregnated resin impregnated into the insulating base material 1-5 to thicken, and during that time, the resin flows out, causing defects such as micro voids and large voids in the coil insulating layer. There are some remaining drawbacks. If defects remain in the coil insulation layer, partial discharge will occur within the absolute RM.
The electric field resistance of the coil insulating layer decreases due to discharge deterioration. Additionally, voids and voids impede the thermal conductivity of the insulating layer, leading to an increase in the temperature of the coil conductor, accelerating thermal deterioration of the coil insulating layer, and reducing the withstand voltage performance and mechanical strength against thermal stress. Therefore, in the process of forming the coil insulating layer, it is important to develop a structure that eliminates these disadvantages.

An object of the present invention is to obtain a coil insulating layer free from defects such as voids and gaps by improving the insulating tape used.

[Means to solve the problem]

In order to solve the above problems, this Zenmeiban has developed an insulating base material in which an insulating tape, in which a reinforcing material and a main insulating base material layer made of laminated mica foil are bonded together using a binder, is wrapped around a shaped coil conductor. In the coil insulating layer formed by impregnating and solidifying the layer with an impregnating resin, the insulating tape contains an accelerator consisting of a tertiary amine and a metal complex that has been applied and impregnated onto the main insulating base layer in advance. shall be.

[Effect]

In the above-mentioned means 8, an accelerator is added to the main insulating base layer made of laminated mica foil of the insulating tape, with a mixture of benzyldimethylamine as a tertiary amine and a metal complex such as a metal octylate in a predetermined ratio. By coating or impregnating a predetermined amount of this insulating tape on the shaped coil conductor, when the insulating base material layer, which is wrapped around the shaped coil conductor, is impregnated with thermosetting epoxy resin as the impregnating resin, the accelerator and impregnating Since the impregnating resin gradually reacts with the resin and increasing the viscosity of the impregnating resin, leakage of the impregnating resin from the insulating layer of the coil taken out from the impregnating tank is prevented. In addition, when the coil is placed in a heat curing furnace and heated to a predetermined curing temperature, since the impregnated resin has been thickened in advance, the viscosity decreases little due to temperature rise, and the accelerator increases as the temperature rises. Because it is activated and the reaction is promoted, the flow and release of the impregnated resin is suppressed.

Therefore, the generation of voids and voids caused by the flow of the impregnated resin is eliminated.

〔Example〕

The present invention will be explained below based on examples.

FIG. 1 is an enlarged sectional view of a coil insulating layer for explaining the present invention in detail. In fig.

Reference numeral 11 denotes an insulating tape, which includes a reinforcing layer 12 made of a polyimide film several tens of μm thick, a main insulating base layer 13 made of laminated mica foil, and a binder 1 for bonding the two together.
It is formed as a layered body of 4.

As the binder 14, a mixed resin consisting of a mixed resin of a polyfunctional maleimide and a polyfunctional cyanate ester and an epoxy resin (see JP-A-61-266051), an epoxy resin, a polyimide resin.

Alternatively, a thermosetting resin made of silicone resin is used. In this case, as little binder as possible is deposited so as to leave enough unimpregnated parts to serve as passageways for the subsequent impregnating resin 18.

Further, as the accelerator 16 applied or impregnated on the main insulating base material layer 13, for example, benzyldimethylamine as a tertiary amine and a metal octylate as a metal complex are mixed in a mixing ratio of, for example, 1:1. A mixture of accelerators is used, for example 0.03 to 0 per square meter.
．． 5 parts by weight are uniformly spread or impregnated onto the main insulating base layer.

The insulating tape 11 thus formed is tightly wound on the surface of the shaped coil conductor 7 in a half overlap, and an insulating base material layer (tape layer) 15 consisting of multiple layers such as half overlap tape layers 15A and 15B is formed. For example, a thermosetting epoxy resin or the like is impregnated with vacuum pressure as the impregnating resin 18, and then heat curing treatment is performed.

When impregnating the insulating base material layer 15 with the impregnating resin 18, the accelerator and the impregnating resin gradually react and the viscosity of the impregnating resin increases, so that the impregnating resin does not leak from the insulating layer of the coil taken out from the impregnating bath. Output is blocked.

In addition, when the coil is stored in a heat curing furnace and heated to a predetermined curing temperature, since the impregnated resin has been thickened in advance, the viscosity decreases less due to the increase in temperature. Since the accelerator is activated and the reaction is accelerated, the impregnating resin is prevented from flowing out, and therefore the generation of voids and voids caused by the impregnating resin flowing out is eliminated.

Next, the results of a characteristic test of an example coil using a prototype coil will be explained. The example prototype coil used benzyldimethylamine (manufactured by Somar Co., Ltd.) 1 as the tertiary amine.
Accelerator 16, which is prepared by mixing 10 parts by weight of Nikka Octix Zinc (manufactured by Nippon Kagaku Sangyo; trade name) containing 18 parts of zinc as an octylic acid metal salt, per 1 part by weight.
Uniformly apply or impregnate 0.03 to 0.5 parts by weight per square meter. In this case, an epoxy resin or a material to which an appropriate amount of a solvent or the like may be added may be used to adjust the amount of adhesion. In this example, the epoxy resin is Epicor)
828 (manufactured by Yuka Shell Co., Ltd.; trade name) 100 sieves, 1 to 10 sieves and an appropriate amount of solvent were added to the above-mentioned mixed accelerator, and the mixture was adhered to a predetermined amount of accelerator. rear,
Insulating tape 11 was formed by heating to a predetermined temperature and evaporating the solvent. The insulating tape 11 formed as described above was wound around the coil conductor 7 six times in an overlapping manner to form the insulating base material layer 5. The unimpregnated coil, on which the insulating base material layer 5 has been adhered as described above, is impregnated with liquid impregnation resin 18 made of thermosetting epoxy resin under vacuum pressure, and then heated at 150°C.
A coil was manufactured by heat curing treatment at 180°C for 16 hours and 48 hours at 180°C.

Next, as a comparative example, a comparative example prototype coil similar to the example prototype coil was manufactured using the same base material as the example and an insulating tape 1 to which no accelerator was applied.

FIG. 2 is a cross-sectional view of the prototype coil.

FIG. 3 is a characteristic diagram showing the voltage characteristic test results of the dielectric loss tangent obtained with the above-mentioned example prototype coil and comparative example prototype coil. Note that the dielectric loss tangent was measured including the coil end portion where minute voids and gaps are likely to occur. the result,
The example curve A showed stable characteristics with little change in characteristics due to voltage, whereas the comparative example curve B had a large voltage dependence and microvoids and voids existed in the coil insulating layer, and defects occurred in these defects. This shows that the dielectric loss tangent increased as the applied voltage increased due to the partial discharge.

On the other hand, almost no voltage dependence is observed in the example curve A, indicating that the use of the accelerator-treated insulating tape 11 has an excellent defect prevention effect.

〔Effect of the invention〕

As described above, this invention involves insulating a shaped coil conductor by wrapping an insulating tape in which a curing accelerator containing a mixture of a tertiary amine and a metal complex is pre-coated and impregnated on the main insulating base layer made of a laminated mica foil. A base material layer was formed, and a coil insulating layer was formed by resin impregnation and heat curing treatment. As a result, the reaction between the impregnating resin and the accelerator increases the viscosity of the impregnating resin, suppressing the leakage of the impregnating resin after mold release, and further activating the accelerator during heating, suppressing the fluidity of the impregnating resin. This eliminates the problem of the impregnated resin flowing out, which was a problem with conventional technology, especially in areas where the adhesion of the insulating tape is uneven, such as the bends of the coil. It is possible to provide a coil insulating layer for a high-voltage rotating electric machine that does not contain minute voids or gaps and therefore has excellent electrical insulation, good thermal conductivity, and thermal stress resistance.

[Brief explanation of drawings]

Fig. 1 is an enlarged sectional view showing a coil insulating layer according to an embodiment of the present invention, Fig. 2 is a cross-sectional view showing a prototype coil of an embodiment, and Fig. 3 -
4 is a characteristic diagram showing the dielectric loss tangent-voltage characteristics of the example prototype coil in comparison with that of the comparison example prototype coil, and FIG. 4 is an enlarged sectional view showing a conventional coil insulating layer. 1.11... Insulating tape, 2, 12... Reinforcement layer, 3
゜13... Main insulating base material layer, 4.14... Binder, 5
．． 15... Insulating base material layer (insulating tape layer), 7... Shaped coil conductor, 8, 18... Impregnated resin, 1o... Coil insulating layer, 16... Accelerator, 7. -〉, Figure Voltage (kV) Figure 3

Claims (1)

[Claims] 1) A coil insulating layer is formed by impregnating and solidifying an insulating base material layer with an insulating base material layer in which a reinforcing material and a main insulating base material layer consisting of a laminated mica foil are laminated together with an insulating tape around a shaped coil conductor using a binder. 1. A coil insulating layer for a high-voltage rotating electrical machine, wherein the insulating tape contains an accelerator consisting of a tertiary amine and a metal complex, which is coated and impregnated onto the main insulating base layer in advance.