JPH0640727B2 - Method for manufacturing randomly wound coil of high-voltage rotating electric machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a randomly wound coil of a high-voltage rotating electric machine whose rated voltage exceeds 3 KV, and more particularly to an insulating coating layer of a round conductor forming a randomly wound coil conductor.

[Conventional technology]

The insulation method for high-voltage rotating electric machine coils of 3 KV or more is generally an insulation method that attaches importance to corona resistance because of its high voltage. That is, as shown in the sectional view of the molded high-voltage rotating electric machine coil in FIG.
A molded coil conductor 35 in which the insulated coating conductor 31 having been subjected to is wound in a plurality of turns is formed, a ground insulating tape layer 37 is wound, and a thermosetting resin 38 such as an epoxy resin is impregnated and cured to form a ground insulating layer 40. It is a method to let. As described above, in the general high-voltage rotating electric machine insulation method, the wire insulation consisting of the insulation coating 33 and the ground insulation layer 40 are formed, and as the insulation material of each part, a mica material having excellent corona resistance is used, and Due to resin impregnation, it is an insulation system with almost no voids. However, when manufactured by such a method, there are many work processes such as alignment coil winding, wire hardening, ground insulating taping, resin impregnation, and curing treatment, and it is necessary to use high-quality insulating tape or impregnated resin. In addition, the material cost is increased, and the cost of the rotary electric machine is increased.

Therefore, as a cheaper insulation method, a random winding insulation method using a round wire conductor is known. Generally, this is an insulation method used in low-voltage rotating electric machines, but an insulation-coated conductor (element wire) in which an insulation coating such as enamel is applied to a round wire element conductor is randomly wound and bundled with a binding material such as glass tape. After that, it is placed in the iron core slot through a slot liner such as Aramid paper (commercial Nomex), and then resin impregnated and cured. With this method, it is possible to provide an inexpensive rotating electric machine with a low work process and material cost, but it is possible to provide a gap between the round wire element conductors by using the above-described conventional insulation method using a rectangular conductor. Since it is difficult to form a dense structure with no gaps and voids are easily generated between the wire conductors, the insulation reliability must depend on the insulation coating material of the wire conductors, and this insulation coating layer is resistant to There is a problem that it cannot be applied to a high voltage rotating electric machine coil of 3 KV or more as it is because it is not an insulation method considering corona property.

In addition, it is conceivable to use a film winding wire as an insulation method to improve the corona resistance, which is a problem here, but in the case of film coating, once corona discharge occurs, the film insulation is eroded in a short time and leads to dielectric breakdown. Therefore, special care is taken to prevent damage during irregular winding work, but there is still the problem that it is difficult to completely fill the films with resin and eliminate voids due to resin impregnation. So, if you just use film winding, it is 3KV
The insulation of the above high-voltage rotating electric machine has a drawback of lacking reliability.

[Problems to be solved by the invention]

In order to further improve the corona resistance of the wire insulation, which was a problem in the prior art, a mica-wound electric wire wound with mica tape with a glass fiber cloth as a base material and mica paper attached to it Tried to form. However, it is difficult to wind the insulating coating layer tightly around the round conductor due to the poor elongation of the glass fiber cloth, and at the time of winding processing, the insulating coating floats to form a gap,
The impregnated resin that once filled this gap during resin impregnation also flows out when it is heat-cured, resulting in a problem that it becomes a wire insulation coating layer with many gaps. Since it easily occurs, it is difficult to obtain an insulation system with excellent corona resistance despite using an insulating material with excellent corona resistance. Therefore, it is reliable as a random winding coil for a high-voltage rotating electric machine of 3 KV or more. It turned out to be lacking.

An object of the present invention is to obtain an insulation system excellent in reliability and economy as a rotating electric machine coil of 3 KV or more by eliminating the gap between the insulating coating layers of the round conductor and the gap between the round conductors.

[Means for solving problems]

In order to solve the above-mentioned problems, according to the present invention, a randomly wound coil conductor bundled with a binding tape layer is inserted into a slot groove covered with a slot liner after randomly winding an insulating coated round conductor. Then, in a coil formed by impregnating and hardening a thermosetting resin after mounting a wedge, a binding tape and a slot liner which have been previously subjected to a hardening catalyst of the thermosetting resin are used, and the insulating coating of the round conductor is polyester. A material comprising a base material obtained by applying the curing catalyst to a woven cloth having heat shrinkability composed of fibers and glass fibers, and an insulating coating material obtained by attaching mica paper to the base material with a binder made of a semi-cured resin. And

[Action]

In the above configuration, the insulating coating layer of the round conductor is formed by using a heat-shrinkable woven cloth as a base material and using a heat-shrinkable insulating coating tape in which mica paper is adhered to the base material. As a result, even if the insulating coating layer of the obtained mica-wound electric wire is not completely adhered to the round conductor and the insulating coating layer floats up during the irregular winding process, the base material during the heat curing treatment of the resin impregnation is performed. The defects are repaired by the shrinkage of the resin, and the insulating layer consisting of the woven fabric and mica paper has high resin impregnation property and liquid retention, so there are few voids in the coated insulating layer and the bundling that constitutes the insulation method. tape,
Since the slot liner and the insulating coating layer of the round conductor have been subjected to a curing catalyst in advance, the retention of the above-mentioned impregnating resin of the coating insulating layer is further improved, and the voids in the slot are filled with the resin, and therefore the corona resistance is improved. It is possible to obtain a randomly wound coil of a high-voltage rotating electric machine having excellent insulation reliability such as.

〔Example〕

 The present invention will be described below based on examples.

FIG. 1 is a sectional view showing a randomly wound coil according to an embodiment of the present invention,
FIG. 2 is a sectional view of an insulating coating material in the embodiment, and FIG. 3 is a side sectional view of a mica wound electric wire in the embodiment. As shown in FIG. 2, the insulating coating material 4 has a thickness of about 0.05 mm to 0.2 mm in which a mica paper 4B is attached to a woven cloth 4A having a heat shrinkability as a base material with a small amount of an adhesive such as an epoxy resin. It is formed into a sheet shape and is cut into a predetermined width for use. The woven fabric 4A is made of a woven fabric of heat-shrinkable polyester fiber and glass fiber, a polyester thread having a thickness of about 0.05 mm to 0.15 mm is used as a warp thread, and a glass thread having the same thickness is used as a weft thread. Both are woven with a density of about 10 to 50, mixed with polyester fibers in the warp, and used with warp and weft polyester fibers with different heat shrinkage. To be done.

As the mica paper 4B, laminated mica or laminated mica mixed with a small amount of aramid fiber is used. Further, the amount of resin as the binder of the mica paper 5 is determined depending on whether the mica paper is vacuum impregnated or dip impregnated in the subsequent resin impregnation step. % Is about 20 to 50% by weight in the case of immersion impregnation, and the semi-curing treatment is performed.

The insulating coating material 4 thus formed is cut into a tape shape, and as shown in FIG. The mica-wound electric wire 1 having the insulating coating layer 3 is formed by performing the operation once to four times.

FIG. 1 is a cross-sectional view of an example randomly wound coil obtained by randomly winding the mica wound wire formed as described above. The mica wound wire (strand) 1 is wound a predetermined number of times using a winding machine. After the random winding, the random winding coil conductor 5 in which the binding tape layer 6 is formed of a binding material such as glass tape is provided in the open type slot groove 10 formed in the iron core 11 of the rotating electric machine, and as the slot liner 7. After being inserted through a mid sheet or a mica sheet, the slot liner 7 is bent to cover the upper surface of the coil conductor 5, and the wedge 12 made of a glass substrate laminated plate or the like is driven into It is fixed in the slot groove 10. A thermosetting resin 8 such as an epoxy resin or a polyester resin is impregnated in the iron core on which the above-mentioned winding is mounted. The impregnation method has been described above, but vacuum impregnation or immersion impregnation method is used, but vacuum impregnation is desirable from the viewpoint of improving reliability, and vacuum after impregnating with vacuum is used to pressurize the liquid surface with nitrogen gas. The pressure impregnation method provides the best characteristics. Further, the resin is heated and cured by using a curing furnace after impregnation, but at the time of curing, it is desired that the thermosetting resin be cured after the insulating coating material is contracted, for example, it is kept at 130 ° C. for about 1 hour. After shrinking the heat-shrinkable woven fabric, the heat setting temperature is about 1
By performing the heat curing treatment of the impregnated resin 8 at 40 to 160 ° C. for about 6 to 16 hours, the randomly wound coil of the high-voltage rotating electric machine fixed to the slot groove 10 and integrated is formed.

In addition, in order to prevent the resin once impregnated from flowing out and to fill the gap in the slot groove, a binding tape, slot liner,
Alternatively, the insulating coating layer is previously treated with a curing catalyst.

FIG. 4 is a characteristic diagram showing the withstand voltage life characteristics of the randomly wound coil of the embodiment in comparison with that of the conventional coil. The vertical axis of the figure shows the applied voltage (dielectric breakdown voltage) and the rated voltage of the test coil. E
The magnification is shown as. A curve 51 shows the characteristics of an example coil using a mica-wound electric wire in which the heat-shrinkable insulating coating material 4 is wound twice in a 1/2 stack, and a curve 52 shows a conventional mica-wound electric wire having no heat-shrinkable property. The characteristics of the example coil 1 used are
A curve 53 shows the characteristics of the comparative example coil 2 using the enamel electric wire. In each case, two sheets of glass-based mica sheets were used as the slot liner, and the epoxy coil was subjected to vacuum pressure impregnation treatment to obtain a test coil. . In the figure, 0.
Comparing the initial breakdown voltage in one hour with the curves, the example coil is about 3.5E, while the comparative coil 1 is about 2.6E and the comparative coil 2 is about 1.8E.
It is as low as E, and the comparative example coil 2 cannot withstand the withstand voltage test of 2E + 1000V required for the high-voltage rotating electric machine coil.
Next, comparing the life times in the vicinity of the rated voltage E, which is a measure of corona resistance at an operating voltage (about 0.58E), the comparison coil 1 has about 2 digits compared to the embodiment coil, and the comparison coil 2 has further The life characteristics are shorter than two digits, and the influence of the difference in the wire insulation coating layer on the withstand voltage life characteristics of the randomly wound coil is apparent. That is, this test result shows that the insulating coating material forming the insulating coating layer of the round conductor has heat shrinkability and resin impregnation property, and after the resin is impregnated with a sufficient amount of resin during the resin impregnation treatment, the impregnated resin is cured prior to curing. In comparison with Comparative Example Coil 1 having a similar insulation coating layer, the insulation coating material heat-shrinks to tightly bind the round conductor, and a dense insulation coating layer is formed to closely surround and surround the round conductor. However, it is conceivable that a randomly wound coil having a high initial breakdown voltage and a long corona life was obtained.

〔The invention's effect〕

As described above, the present invention uses a curing catalyst to pretreat the base material of the insulating coating material that is wound around the binding tape, the slot liner, and the mica winding electric wire that are wound in an insulating manner,
Further, the base material of the insulating coating material of the mica-wound electric wire is a woven cloth having heat shrinkability, and the mica paper is attached to the base material. As a result, the resin, including the base material, has good resin impregnation properties, and the insulation coating contains sufficient impregnated resin without damaging the coating during winding compared to conventional turbulent winding coils that use enamel-coated wires or film-wound wires. As the layer is formed, the insulating coating material heat-shrinks and binds the round conductor prior to the heat curing of the impregnating resin, so that when the impregnating resin is cured, the insulation does not include the voids that closely surround the round conductor. Since the coating layer is formed and the inside of the slot is filled with resin to form a dense structure, a glass-based mica tape that does not have heat shrinkability can be obtained in a high initial stage that cannot be obtained with a conventional random winding coil using an insulating coating material. It is possible to provide a randomly wound coil of a high-voltage rotating electric machine having high withstand voltage and corona resistance and high life performance and high insulation reliability. Further, since the winding coil can be applied to the high-voltage rotating electric machine, which cannot be realized by the conventional winding coil insulating system, the winding can be formed at a lower cost than the conventional shaping coil. Can contribute to cost reduction.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment coil of the present invention, FIG. 2 is a sectional view showing an insulating coating material in the embodiment, and FIG. 3 is a side sectional view of a mica wound electric wire (element wire) in the embodiment. FIG. 4 is a characteristic diagram showing the withstand voltage life characteristics of the example coil in comparison with that of the conventional coil, and FIG. 5 is a sectional view showing the conventional high voltage shaping coil. 1, 31 ...... Mica winding electric wire (strand), 2 ... Round conductor,
3, 33 ... Insulation coating layer, 4 ... Insulation coating material, 4A ...
Heat-shrinkable woven fabric (base material), 4B ... Mica paper, 5 ...
Randomly wound coil conductor, 6 ... Binding tape layer, 7 ... Slot liner, 8 ... Impregnated resin, 10 ... Slot groove, 12 ...
… Wedge.

Claims (1)

[Claims] Claim: What is claimed is: 1. A plurality of insulating coated round conductors are randomly wound, and then a randomly wound coil conductor covered with a binding tape layer is inserted into a slot groove covered with a slot liner, and a wedge is attached, followed by thermosetting. In a method of manufacturing a randomly wound coil obtained by impregnating and curing a resin, a binding tape and a slot liner which have been previously subjected to a curing catalyst of the thermosetting resin are used, and the insulating coating of the round conductor is a polyester fiber and a glass fiber. A high-pressure woven fabric having a heat-shrinking property and a base material obtained by applying the curing catalyst to the base material, and an insulating coating material in which mica paper is attached to the base material with a binder made of a semi-cured resin. A method for manufacturing a randomly wound coil for a rotating electric machine.