JP2001069709A - Dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to have a stable surface corona-preventing layer by reducing a loss per a specific length around a contact part to a specific value or lower irrespective of the resistance rate of the surface corona preventing layer comprising mainly carbon particles and an epoxy resin. SOLUTION: In a surface corona-preventing layer that comprises mainly carton particles and an epoxy resin, no burning occurs if the loss per the length of 1 mm around a contact part is 1W or lower irrespective of its resistance rate. This condition can be satisfied if one or more good contact parts are secured within the range of at least 40 mm when the resistance rate of the surface corona preventing layer is 5 kΩ or lower and within 60 mm in the case of the resistance rate of 1 kΩ or lower. A base member layer as a main ground insulating layer is formed by winding a specified number of times a laminated mica tape made up of mainly glass and film laminated on the surface of a coil conductor 1. In addition, a semiconductive tape in a prepreg state is wound around the base member layer twice to form a surface corona- preventing layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rotating electric machine driven by an inverter.

[0002]

2. Description of the Related Art In a stator coil of a high-voltage rotating electric machine such as an induction motor or a generator, a method of forming an insulating layer includes a method of impregnating a resin with a stator coil alone and a method of not impregnating a stator coil. Is housed in a slot, and the coils are electrically connected to each other, and then the resin is impregnated. In particular, in the stator coil of the full impregnation method, the gap between the stator coil and the iron core slot is filled with a cured product of the impregnating resin, the iron core and the coil are integrated, and the heat conductivity between the coil and the iron core is high, It has excellent cooling performance and has the advantage of simplifying the process of resin impregnation and heat curing, and is widely used.

Conventionally, as disclosed in Japanese Patent Application Laid-Open No. H10-257707, measures have been taken to reduce the potential below the corona discharge starting voltage, for example, by using a method of electrically connecting the surface corona prevention layer to the iron core at one place. ing.

[0004]

By the way, a current for charging the capacitance formed by the coil main insulating layer flows through such a surface corona preventing layer. This charging current increases in proportion to the capacitance of the insulating layer, the voltage and frequency of the applied voltage. When the system is operated with a conventional AC voltage of a commercial frequency, the current value is at most about several tens mA even in all the coils, and there is no problem. However, in a rotating electric machine driven by an inverter, the charging current may be extremely large at several tens A at the peak due to a high frequency component included in the voltage.

[0005] When a portion having a large contact resistance occurs at a contact portion between the surface corona prevention layer and the iron core due to impregnation with a resin, a loss at that portion increases and the temperature rises.
Finally, there is a problem leading to burning.

It is an object of the present invention to provide a rotating electric machine driven by an inverter having a stable surface corona prevention layer.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotating electric machine in which the loss of a contact portion between a surface corona prevention layer and an iron core is made equal to or less than a burnout level of the portion. According to one embodiment of the present invention, means for bonding or adhering the surface corona preventing layer to the iron core before impregnation with the resin, means for lowering the resistivity of the surface corona preventing layer, and providing the surface corona preventing layer with a high dielectric constant It is a combination of a means to which semiconductive particles are added and a means of combining them.

According to the experimental results of the present inventors, in the surface corona prevention layer mainly composed of carbon particles and epoxy resin, the loss per 1 mm of the circumference of the contact portion is 1 W regardless of the resistivity. It was confirmed that if it was below, no burning occurred. The condition is that at least one good contact portion should be secured within a range of at least 40 mm when the resistivity of the surface corona prevention layer is 5 kΩ or less, and within a range of 60 mm when the resistivity is 1 kΩ or less. Was found to be satisfied. Therefore, in order to satisfy this condition, if the corona surface prevention layer and the iron core are bonded or adhered before the resin impregnation, even if the contact resistance increases in portions other than the adhesion and the adhered portion due to the subsequent resin impregnation, the Since the current flowing into the contact portion having the increased contact resistance can be maintained at a low value, the loss in this portion can be suppressed to a level that does not cause burnout. If the resistance of the surface corona prevention layer is reduced, the contact resistance can be reduced even with the same contact area, so that there is an effect that the loss can be reduced. When particles having a high dielectric constant such as silicon carbide, zinc oxide or titanium oxide are added to the surface corona prevention layer, the coil charging current is shunted by capacitive coupling of the semiconductive corona prevention layer. Therefore, it is possible to reduce the current flowing through the resistance component of the surface corona prevention layer that causes the loss, and it is possible to widen the necessary range of the good contact portion. In addition,
The present invention is further described by the following description.

[0009]

Embodiments of the present invention will be described below.

Comparative Example First, a comparative example of the present invention will be described with reference to FIGS.

FIG. 6 is a cross-sectional view showing a state of a stator coil of a high-pressure rotating machine of a comparative example according to an integral injection and impregnation method. In FIG. 6, a stator coil 20 has a rectangular parallelepiped coil side portion (referred to as a slot portion) formed in a stator core 40 so as to extend radially and in the rotation axis direction into a slot 60.
Prior to insertion into the coil 2, a mica tape such as a glass-based mica or a film-based mica is wound on the coil conductor 1 using an insulated wire wound a plurality of times or using an aligned conductor that has undergone label transition. A base layer of a ground insulating layer is wound a predetermined number of times, and a semi-conductive tape such as a semi-conductive glass tape, a semi-conductive film tape, or a semi-conductive non-woven tape is formed to a predetermined thickness around the base layer. The wound substrate layer of the surface corona prevention layer 3 is formed. The stator coil in the non-impregnated state formed in this way has two slots on the upper and lower sides by interposing an insulating material between the coils between the coils.
And the opening of the slot 602 is inserted into the insulating material 1 under the wedge.
1 and closed with a wedge 41, and the coil is fixed to the stator core 4
After fixing to 0 and making electrical connection between the coils, a resin impregnation process by a full impregnation method is performed.

In the resin impregnation process, the stator core 40 wound with the stator coil 20 is housed in a vacuum impregnation tank, dried in vacuum, and then impregnated with a thermosetting impregnating resin such as epoxy resin at a predetermined temperature in vacuum. The impregnating bath is pressurized and impregnated, and then transferred from the impregnating bath to a curing bath at a predetermined temperature to heat and cure the impregnated resin. According to this method, the stator coil 20 having the main insulating layer 2 impregnated in the voidless is formed, and is bonded to the inner wall surface of the slot 602 by the cured product of the impregnated resin layer impregnated in the gap with the iron core 40. The stator winding of the high-voltage rotating electric machine in which the iron core 40 and the stator coil 20 are integrated is formed. However, when the resin is impregnated between the surface corona prevention layer 3 formed outside the main insulating layer and the iron core 40 and the electrical contact between the two becomes poor, the potential of the surface corona prevention layer 3 increases and corona discharge occurs. appear.

An end corona prevention layer 50 is provided on the side of the surface corona prevention layer 3 where the coil extends.

A current for charging the capacitance formed by the coil main insulating layer 2 flows through the surface corona prevention layer 3. This charging current increases in proportion to the capacitance of the insulating layer, the voltage and frequency of the applied voltage. When the system is operated with a conventional AC voltage of a commercial frequency, the current value is at most about several tens mA even in all the coils, and there is no problem.
However, in a rotating electric machine driven by an inverter,
Due to the high frequency components included in the voltage, the charging current may be extremely large, for example, several tens of amps at the peak.
Such a large current flows to the stator core 40 through the surface corona prevention layer 3, but the current density becomes high especially at the contact portion between the surface corona prevention layer 3 and the stator core 40, and the surface corona is overheated. The problem that the prevention layer 3 was burned out occurred. Therefore, it is important to evaluate the electrical conductivity of the surface corona prevention layer 3 and the contact portion between the surface corona prevention layer 3 and the stator core 40. However, it was not known that there was such a problem in the past, and therefore, no study was conducted. To simply evaluate the electrical conductivity, create a model simulating the contact area, apply the required current to the stator core from the surface corona prevention layer, and consider the area of the contact area to determine the allowable charging current per unit surface area. It is generally done in a determined way. However, in such a method, considering an equivalent circuit, the contact resistance formed at the contact portion evaluates the conduction characteristics of the circuits connected in parallel. In this case, the conduction current is distributed in proportion to the reciprocal of the contact resistance. If there is a good contact, the current in that portion increases, and the overall conductivity is evaluated by this characteristic. The problems of such an evaluation method are as follows. That is, when the contact resistance is modeled assuming that the contact portion with the stator core has a circular shape with a radius a, where R is the surface resistivity of the semiconductive and surface corona prevention layer, R · (2πa ). Therefore, for example, when contact is made at a radius of a1, a2 with a gap of 10 mm and the ratio of a1, a2 is 100: 1, the ratio of the contact resistance is 1: 100, and the ratio of the current flowing through the contact point is The ratio becomes 100: 1, and a large current flows through the portion a1 having a large radius of the contact portion. Since the loss at the contact is proportional to the product of the square of the current and the reciprocal of the contact resistance, the ratio of the loss at both contact points is 100: 1. That is, the loss in the portion a1 increases. For example, the contact length of the portion a1 is represented by 2πa1 and is proportional to a1. Therefore, the loss per unit length of the contact portion, that is, the ratio of the loss density is 1: 1. These are summarized in Table 1. That is, the loss density of each contact portion is the same irrespective of the difference in contact resistance, and it does not mean that any portion has a large loss density.

[0015]

[Table 1]

However, as a result of a detailed study of the distribution of the current flowing through the surface corona prevention layer, it was found that the electrical conductivity of the surface corona prevention layer could not be evaluated by such a method.
As shown in FIG. 7, the contact portion 60 with the stator core 40 has a radius a
Considering the disk-shaped insulating layer, the potential of the surface corona prevention layer 3 is changed by the current for charging the capacitance of the insulating layer.

## EQU1 ##

This is illustrated in FIG. 8, where the potential of the surface corona prevention layer 3 increases as the distance from the contact portion increases. When there are adjacent contact portions having different contact resistances with the radiuses a1 and a2 of the respective contact portions 60, the charging current of the insulating layer near the respective contact portions flows to the respective contact portions. The branch is considered to be a position where the potential of the surface corona prevention layer 3 becomes the same as shown in FIG. 1 as above
At the contact portion separated by 0 mm, the ratio of a1 and a2 is 100:
Analyzing the case of 1 as an example, the ratio of the flowing current is 3.
7: 1. Since it is not proportional to the reciprocal of the contact resistance,
The loss ratio is 1: 7.2, which is larger at the portion where the radius of the contact portion is smaller. Since the length of the contact portion is smaller at the portion where the contact resistance is larger, it has been found that the loss density per unit length of the contact portion is 1: 724. Table 2 summarizes these. That is, it can be said that the loss in the portion where the radius of the contact portion is small becomes relatively large, and the loss becomes larger as the radius becomes smaller, that is, as the contact resistance becomes larger. This is because the current that charges the capacitance formed by the insulating layer near the contact part flows into the contact part regardless of the magnitude of the contact resistance. It is to become. Therefore, when the resin is impregnated and a portion where the contact resistance between the surface corona prevention layer 3 and the iron core 40 is large is generated, the loss at that portion is increased and the temperature is increased. Eventually, it will lead to burning.

[0019]

[Table 2]

The present invention provides a rotating electric machine in which the loss of the contact portion between the surface corona prevention layer and the iron core is made equal to or less than the burnout level of that portion.

Embodiment 1 FIG. 1 shows an embodiment of the present invention. In FIG. 1, a laminated mica tape having glass and a film as a base material is wound a predetermined number of times on the surface of a coil conductor 1 using an aligned conductor that has been wound a plurality of times or has undergone a label transition, in which an insulated wire is wound. A base layer of the ground main insulating layer was formed, and a prepreg-shaped semiconductive tape was wound twice therearound to form a surface corona prevention layer 3. For this semiconductive tape, a prepreg-like epoxy resin in which carbon was mixed into a glass substrate was used. This resin is not limited to epoxy, polyester,
Resin such as modified polyimide is also possible. Further, a film tape such as polyester or a non-woven fabric tape such as polyamide can be applied to the substrate. The thus formed stator coil in an unimpregnated state (also referred to as a white coil).
The two upper and lower strips were housed in a slot with a semiconductive laminated plate 4 interposed between the coils, and the opening of the slot was closed with a wedge 41 via an insulating material 11 below the wedge to fix the white coil to the stator core 40. Then, after the coils were electrically connected to each other, a heat drying treatment was performed before the impregnation. During this heating, the semiconductive prepreg-like epoxy resin was softened and cured while filling the gap with the stator core 40, and a good electrical connection state was obtained. Thereafter, the stator core after the winding of the stator coil was housed in a vacuum impregnation tank, dried under vacuum, and then vacuum impregnated with a thermosetting impregnating resin such as an epoxy resin at a predetermined temperature. Further, the impregnation tank was pressurized and impregnated, and then transferred from the impregnation tank to a curing tank at a predetermined temperature to heat and cure the impregnated resin. By the above procedure, the stator coil 20 having the coil insulating layer 2 composed of the main insulating layer impregnated in the voidless is formed. At the same time, the surface corona prevention layer 3
Since the contact portion between the metal core and the iron core 40 is adhered before the resin impregnation, this portion is not impregnated with the resin, and the contact resistance does not increase due to the resin impregnation.

Embodiment 2 FIG. 2 shows another embodiment of the present invention. In FIG. 2, a pair of a predetermined number of turns of a mica tape having glass and a film as a base material is wound on the surface of a coil conductor 1 having an aligned conductor in which an insulated wire is wound a plurality of times or has undergone a label transition. A base layer of the ground insulating layer was formed, and a semiconductive tape material having rubber elasticity was wound around the base layer once to form a surface corona prevention layer 3. This semiconductive tape is
It is formed by applying silicone rubber kneaded with carbon powder on a glass substrate. The rubber is not limited to silicone, but may be formed by kneading carbon particles, carbon fibers, metal particles such as iron, and a mixture thereof into acryl, ethylene propylene elastomer, or the like. The non-impregnated stator coil thus formed is housed in a slot with the upper and lower two strips interposed between the coils with the semiconductive laminated plate 4 interposed therebetween, and the opening of the slot is formed with a wedge 41 via a lower wedge insulating material 11. The covering white coil was fixed to the stator core 40. After the coils were electrically connected to each other, a heat-drying process before impregnation was performed. After that, the stator core after winding the stator coil is housed in a vacuum impregnation tank, vacuum-dried, and then vacuum impregnated with a thermosetting impregnating resin such as epoxy resin at a predetermined temperature, and the impregnating tank is pressurized. And impregnated under pressure.
Thereafter, the stator coil 2 having a coil insulating layer 2 having a main insulating layer impregnated in a voidless material is transferred from the impregnating tank to a curing tank at a predetermined temperature and heat-cured to cure the impregnated resin.
0 is formed. Since the surface corona prevention layer 3 is in close contact with the stator core 40 by the elastic force of rubber, the contact resistance of this portion does not increase due to resin impregnation. on the other hand,
When the temperature of the stator coil 20 rises and thermally expands and a thermal stress acts between the stator coil 20 and the stator core 40,
While the thermal stress is small, it is absorbed by the deformation of the rubber-like elastic body. If the thermal stress further increases, the rubber-like elastic body is cut inside. If it is not a rubber-like elastic body or if it is cut at a part other than the semiconductive surface corona prevention layer,
Since the insulating film is provided in the vicinity of the cut surface, even if the cut portion is slightly displaced, the electrical contact of this portion is impaired. However, according to the present invention, since the semiconductive rubber-like elastic portion is exposed on the cut surface, the contact position between the surface corona prevention layer 3 and the stator core 40 is relatively displaced by thermal expansion. However, since the electrical contact is maintained at the new contact position, the contact density can be kept large regardless of the operation conditions. Third Embodiment FIG. 3 shows another embodiment. In FIG. 3, a pair of a predetermined number of turns of a mica tape composed of a glass and a film as a base material is wound on the surface of a coil conductor 1 having an aligned conductor in which an insulated wire is wound a plurality of times or has undergone a label transition. Forming a base layer of the coil insulating layer 2 having a landown insulating layer,
Further, a base layer of the surface corona prevention layer 3 in which a semiconductive tape is wound with a predetermined thickness is formed therearound. For this semiconductive tape, an epoxy resin in which carbon was mixed into a glass substrate was used. This resin is not limited to epoxy, but may be a resin such as polyester or modified polyimide.
In addition, a film tape of polyester or the like or a non-woven tape of polyamide or the like can be used as the base material. The non-impregnated stator coil thus formed was housed in the slot 602 via the semiconductive laminate 4. After the insertion, a semiconductive thermosetting resin mixed with carbon powder was poured between the semiconductive tape and the iron core. After that, the opening of the slot housed in the slot is closed with a wedge 41 via a lower wedge insulating material 11, the white coil is fixed to the stator core, and the coils are electrically connected to each other. The semiconductive thermosetting resin between the semiconductive tape and the iron core was cured, and a good electrical contact state was obtained at this portion. After that, the stator core after winding the stator coil is housed in a vacuum impregnation tank, and after vacuum drying, vacuum impregnated with a thermosetting impregnating resin such as epoxy resin at a predetermined temperature,
Further, the impregnation tank was pressurized and impregnated. Thereafter, the main insulating layer 2 impregnated in the voidless is transferred from the impregnating tank to a curing tank at a predetermined temperature and heat-cured to cure the impregnated resin.
Is formed. Since the surface corona prevention layer 3 is bonded to the stator core 40 with the semiconductive resin 5 having a semiconductive thermosetting resin before the resin impregnation, the resin portion is not impregnated with the resin. In a portion where the semiconductive thermosetting resin layer is not provided, the coil 20 is
The stator winding of the high-voltage rotating electric machine in which the stator core 40 and the stator coil 20 were integrated with each other was joined to the inner wall surface of the slot by the cured material of the impregnated resin impregnated in the gap with zero.

In this embodiment, instead of pouring a semiconductive thermosetting resin, a U-shaped or strip-shaped prepreg-shaped semiconductive sheet is inserted between the coil surface semiconductive tape and the iron core. The same effect was obtained when cured. The prepreg-shaped semiconductive sheet used was a film tape of glass, polyester or the like, or a non-woven tape base material of polyamide or the like coated with a prepreg-like epoxy resin mixed with carbon. The resin is not limited to epoxy, but resins such as polyester and modified polyimide can also be applied.

Embodiment 4 FIG. 4 shows another embodiment. In FIG. 4, a pair of a predetermined number of turns of a mica tape composed of a glass and a film as a base material is wound on the surface of a coil conductor 1 having an aligned conductor that has been wound a plurality of times or has undergone label transition on an insulated wire. The base layer of the coil insulating layer 2 having the ground insulating layer was formed. Further, a base layer of a surface corona prevention layer 3 in which a semiconductive tape is wound with a predetermined thickness is formed therearound. For this semiconductive tape, an epoxy resin in which carbon was mixed into a glass substrate was used. This resin is not limited to epoxy,
Resins such as polyester and modified polyimide are also possible. The base material is a film tape such as polyester,
Alternatively, a non-woven tape such as polyamide can be used. The non-impregnated stator coil thus formed was inserted into the slot 602 together with the corrugated semiconductive laminate 6 having semiconductive elasticity. At the same time, the upper and lower two strips are housed in a slot with a semiconductive laminated plate 4 interposed between the coils, and the opening of the slot is closed with a wedge 41 via a lower wedge insulating material 11, and the white coil is fixed to the stator core 40. Fixed. After the coils were electrically connected to each other, a heat-drying process before impregnation was performed. After that, the stator core wound with the stator coil is housed in a vacuum impregnation tank, and after vacuum drying, a thermosetting impregnating resin such as epoxy resin is vacuum impregnated at a predetermined temperature, and the impregnation tank is further pressurized. Pressure impregnation was performed. Thereafter, the stator coil 20 having the main insulating layer 2 impregnated in the voidless is formed by transferring the resin from the impregnation bath to a curing bath at a predetermined temperature and heating and curing the impregnated resin. Even after the resin impregnation, a good electrical contact state is maintained at the contact portion between the surface corona prevention layer 3 and the stator core 40 and the elastic corrugated semiconductive laminate 6. The coil 20 is coupled to the inner wall surface of the slot by a cured product of the impregnated resin impregnated in the gap between the iron core 40 and forms a stator winding of the high-voltage rotating electric machine in which the stator iron core 40 and the stator coil 20 are integrated. did it.

Further, a corrugated semiconductive material 6 having elasticity is provided.
If a semi-conductive laminate is placed on the coil side of the laminate,
Stress concentration due to elasticity can be prevented, and the resin impregnating property of the base insulating layer with respect to the ground can be improved.

Embodiment 5 FIG. 5 shows another embodiment of the present invention. In FIG. 5, a pair of a predetermined number of turns of a laminated mica tape having glass and a film as a base material on the surface of a coil conductor 1 having an aligned conductor in which an insulated wire is wound a plurality of times or has undergone label transition. A base layer of the coil insulating layer 2 having a ground insulating layer is formed, and a semiconductive tape-like material composed of an epoxy resin containing carbon particles and silicon carbide and a base is wound once around the base layer to prevent surface corona. The base material of the layer 8 was used. The resin of the semiconductive tape is not limited to epoxy, but may be a resin such as polyester or modified polyimide. Further, a film tape such as polyester or a non-woven fabric tape such as polyamide can be applied to the substrate. Further, instead of silicon carbide, particles having a high dielectric constant such as zinc oxide or titanium oxide can be used. The non-impregnated stator coil formed in this way has the upper and lower two strips between the coil and the semiconductive laminate 4.
The white coil was fixed to the stator core 40 by closing the opening of the slot with a wedge via the insulating material 11 below the wedge. After the coils were electrically connected to each other, a heat-drying process before impregnation was performed. After that, the stator core after winding the stator coil is housed in a vacuum impregnation tank, vacuum-dried, and then vacuum impregnated with a thermosetting impregnating resin such as epoxy resin at a predetermined temperature, and the impregnating tank is pressurized. And impregnated under pressure. Thereafter, the stator coil 20 having the main insulating layer 2 impregnated in the voidless is transferred from the impregnating tank to a curing tank at a predetermined temperature and heat-cured to cure the impregnated resin.
Is formed. Since the current flowing through the semiconductive liner 8 containing the high dielectric constant particles serving as the surface corona preventing layer also flows through the capacitance component formed by the high dielectric constant particles, the current flowing through the resistance component can be reduced, and the surface corona preventing layer can be reduced. The loss of the contact portion between the conductive liner 8 containing high inductive conductivity particles and the iron core 40 can be reduced.

Embodiment 6 FIG. 10 shows another embodiment of the present invention. In FIG. 10, a pair of a predetermined number of times of winding a laminated mica tape based on glass and a film on the surface of a coil conductor 1 having an aligned conductor that has been wound a plurality of times or has undergone a label transition on an insulated wire. A base layer of a coil insulating layer 2 having a land-main insulating layer is formed, and a semiconductive tape-like material comprising an epoxy resin containing carbon particles and a base material is wound once around the base layer to form a surface corona prevention layer 3. Material. The resin of the semiconductive tape is not limited to epoxy, but may be a resin such as polyester or modified polyimide. Further, a film tape such as polyester or a non-woven fabric tape such as polyamide can be applied to the substrate. The non-impregnated stator coil thus formed is housed in a slot via the semiconductive liner 9 having no surface protrusion, and the upper and lower two strips are housed in the slot with the semiconductive laminate 4 interposed between the coils. Was sealed with a wedge via an insulating material 11 under the wedge, and the white coil was fixed to the stator core 40. The semiconductive liner is a semiconductive resin with at least carbon particles filled in a resin such as epoxy, polyester, or modified polyimide, and is applied to a film or nonwoven fabric of polyester or polyamide, etc., which is punched at appropriate intervals by punching. Or at least carbon particles on a non-woven fabric obtained by mixing fibrous carbon fibers with polyester or polyamide fibers.
A material in which a semiconductive resin filled in a resin such as polyester, modified polyimide, or the like is applied, and the resistance value in the surface and in the direction of the penetrating layer is a required value or less. At the same time, it is possible to insert a coil having a small gap between the coil iron cores into the slot by using a material having no protrusion on the surface.
After the coils were electrically connected to each other, a heat-drying process before impregnation was performed. After that, the stator core after winding the stator coil is housed in a vacuum impregnation tank, vacuum-dried, and then vacuum impregnated with a thermosetting impregnating resin such as epoxy resin at a predetermined temperature, and the impregnating tank is pressurized. And impregnated under pressure. Thereafter, the stator coil 20 having the main insulating layer 2 impregnated in the voidless is formed by transferring the resin from the impregnation bath to a curing bath at a predetermined temperature and heating and curing the impregnated resin. Since a coil having a small gap between the coil and the iron core can be inserted into the slot through a liner without protrusions, the surface corona prevention layer 3 as the outermost layer of the coil can be inserted through the semi-conductive liner 9 without surface protrusion before the core is impregnated with the resin. Therefore, the resin is not impregnated in this portion, and the contact resistance does not increase due to the resin impregnation. Further, when the semiconductive liner is provided with many irregularities in a crepe shape, the semiconductive liner can be brought into contact with the iron core at many protruding portions. Since the entire surface of the semiconductive liner 9 without surface protrusions is semiconductive, the current does not vary depending on the contact position. Also, if the temperature of the rotating electrical machine rises during use and the slot width increases, the interface with the film in the mica main insulating layer, which has relatively low adhesive strength, is peeled off, preventing this surface corona. The electrical contact between the layer 3 and the stator core 40 does not separate.

Embodiment 7 FIG. 11 shows another embodiment of the present invention. In FIG. 11, a pair of a predetermined number of times of winding a laminated mica tape based on glass and a film on the surface of a coil conductor 1 having an aligned conductor that has been wound a plurality of times or has undergone a label transition on an insulated wire. A base layer of the coil insulating layer 2 having a land-main insulating layer is formed, and a semiconductive tape-like material composed of an epoxy resin containing carbon particles and a base is wound once around the base layer. It was a substrate layer. The resin of the semiconductive tape is not limited to epoxy, but may be a resin such as polyester or modified polyimide. Further, a film tape such as polyester or a non-woven fabric tape such as polyamide can be applied to the substrate. The stator coil in the unimpregnated state thus formed is inserted into a slot by interposing the semi-conductive laminated plate 4 between the upper and lower coils through the release semi-conductive liner 10 having the semi-conductive liner. The opening of the stored slot was closed with a wedge via an insulating material 11 under the wedge, and the white coil was fixed to the stator core 40. The semiconductive liner is a semiconductive resin with at least carbon particles filled in a resin such as epoxy, polyester, or modified polyimide, and is applied to a film or nonwoven fabric of polyester or polyamide, etc., which is punched at appropriate intervals by punching. Or a non-woven fabric obtained by mixing fibrous carbon fibers with polyester or polyamide fibers and coated with a semiconductive resin filled with at least carbon particles in a resin such as epoxy, polyester, or modified polyimide. It is a material whose resistance value in the direction is less than a required value. At the same time, it is possible to insert a coil having a small gap between the coil iron cores into the slot by using a material having no protrusion on the surface. Further, the semiconductive liner 10 was coated with a releasable semiconductive resin 15 on the surface on the coil side and near the iron core end of the slot. The releasable semiconductive resin is obtained by filling semiconductive particles such as carbon particles in silicone or fluorine resin. After the coils were electrically connected to each other, a heat-drying process before impregnation was performed. After that, the stator core after winding the stator coil is housed in a vacuum impregnation tank, vacuum-dried, and then vacuum impregnated with a thermosetting impregnating resin such as epoxy resin at a predetermined temperature, and the impregnating tank is pressurized. And impregnated under pressure. Thereafter, the stator coil 20 having the main insulating layer 2 impregnated in the voidless is formed by transferring the resin from the impregnation bath to a curing bath at a predetermined temperature and heating and curing the impregnated resin. Since the coil having a small gap between the coil and the iron core can be inserted into the slot through the liner without the protrusion, the surface corona prevention layer 3 as the outermost layer of the coil can be inserted through the mold release semiconductive liner 10 before the resin impregnation. Therefore, the resin is not impregnated in this portion, and the contact resistance does not increase due to the resin impregnation. Since the entire surface of the releasable semiconductive liner 10 is semiconductive, the current is not biased depending on the contact position. Also, the temperature of the rotating electric machine rises during use,
When the slot width becomes large, the interface with the film in the mica main insulating layer having a relatively low adhesive strength is peeled off, so that the electrical contact between the surface corona prevention layer 3 and the iron core 40 is peeled off. I will not do it. Further, when the stator coil expands from the iron core, the end of the iron core where a large shear force acts is cut by the releasable semiconductive resin portion 15, but since the cut surface is semiconductive, the electrical contact is made. Is maintained, and the contact resistance does not increase.

Embodiment 8 FIG. 12 shows another embodiment of the present invention. This is applied to a stator of a variable speed generator in which a low frequency AC voltage generated in a circuit using a semiconductor switching element is applied to a rotor coil. The stator coil is a single unit with a ground insulation layer 1
2 etc. were formed. The ground insulating layer 2 existing on the outer periphery of the coil conductor 1 is a resin-impregnated layer mainly composed of mica. A semiconductive surface corona prevention layer 3 is arranged on the outer periphery. The coil surface corona prevention layer 3 was formed of a semiconductive tape having a configuration in which a glass particle or a polyamide nonwoven fabric was coated with carbon particles or a mixture of carbon particles and carbon fibers. The semiconductive laminate 4 was arranged between the bottom surface of the lower coil and the slot wall and between the upper and lower coils, and was placed in the slot in two upper and lower sections. The resistivity of the semiconductive laminate 4 is 8 kΩ. After the coil was inserted into the slot, the semiconductive laminate 12 coated with the semiconductive resin 16 was inserted into the gap between the slot wall on one side and the coil. The resistivity of the laminate 12 was 8 kΩ, and the resistivity of the semiconductive resin 16 was 5 kΩ. A corrugated semiconductive elastic laminate 13 was inserted into the gap between the opposite slot wall and the coil. The elastic modulus of the semiconductive elastic laminate 13 is 3 kg / cm2.
, And the resistivity is 8 kΩ. Further, after the corrugated insulating elastic laminated plate 14 and the wedge lower insulating laminated plate 11 were arranged between the wedge and the upper coil from the wedge side, the wedge 41 was driven. Thereafter, the coil end was connected.

Ninth Embodiment FIG. 13 shows another embodiment according to the present invention. This is applied to a stator of a variable speed generator in which a low frequency AC voltage generated in a circuit using a semiconductor switching element is applied to a rotor coil. As for the stator coil, the main insulating layer 2 and the like were formed on the outer periphery of the conductor coil 1 alone. Ground insulation layer 2
It is a resin impregnated layer mainly composed of mica. A semiconductive surface corona prevention layer 3 is arranged on the outer periphery. The coil was formed of a semiconductive tape having a structure in which a surface corona prevention layer 3 was formed by coating a fluffed glass tape base material with carbon particles or a mixture of carbon particles and carbon fiber. The semiconductive laminate 4 was disposed between the bottom surface of the lower coil and the wall of the slot 602 and between the upper and lower coils, and was placed in the slot in two upper and lower sections. The resistivity of the semiconductive laminate 4 is 8 kΩ. After inserting the coil into the slot, the gap between the coil wall on one side and the coil has a corrugated semiconductive elastic laminate 1
3 was inserted. The elastic modulus of the semiconductive elastic laminate 13 is 3 kg / cm2, and the resistivity is 8 kΩ. Furthermore, after disposing the corrugated insulating elastic laminate 14 and the lower insulating laminate 11 from the wedge 41 side between the wedge and the upper coil,
I wedge 41. Thereafter, the coil end was connected.

Embodiment 10 FIG. 14 shows another embodiment of the present invention. In FIG. 14, a pair of a predetermined number of turns of a mica tape composed of glass and a film as a base material is wound on the surface of a coil conductor 1 having an aligned conductor in which an insulated wire is wound a plurality of times or has a label transition. A base layer of a coil insulating layer 2 having a land-main insulating layer is formed, and a semiconductive tape-like material comprising an epoxy resin containing carbon particles and a base material is wound once around the base layer to form a surface corona prevention layer 3. Material. The resin of the semiconductive tape is not limited to epoxy, but may be a resin such as polyester or modified polyimide. Further, a film tape such as polyester or a non-woven fabric tape such as polyamide can be applied to the substrate. The non-impregnated stator coil thus formed is housed in a slot via a semiconductive liner 7 having rubber elasticity. Was sealed with a wedge via an insulating material 11 under the wedge, and the white coil was fixed to the stator core 40. This semiconductive liner 7
It is formed by applying silicone rubber kneaded with carbon powder on a glass substrate. The rubber is not limited to silicone, but may be formed by kneading carbon particles, carbon fibers, metal particles such as iron, and a mixture thereof into acryl, ethylene propylene elastomer, or the like. After the coils were electrically connected to each other, a heat-drying process before impregnation was performed. After that, the stator core after winding the stator coil is housed in a vacuum impregnation tank, and after vacuum drying, vacuum impregnated with a thermosetting impregnating resin such as an epoxy resin at a predetermined temperature,
Further, the impregnation tank was pressurized and impregnated. Thereafter, the main insulating layer 2 impregnated in the voidless is transferred from the impregnating tank to a curing tank at a predetermined temperature and heat-cured to cure the impregnated resin.
Is formed. Since the surface corona prevention layer 3 as the outermost layer of the coil is in close contact with the stator core 40 via the semiconductive liner 7 having rubber elasticity, the contact resistance of this portion does not increase due to resin impregnation. On the other hand, when the temperature of the stator coil 20 rises and thermally expands, and a thermal stress acts between the stator coil 20 and the stator core 40, while the thermal stress is small, the rubber-like elastic body is deformed. Absorbed. If the thermal stress further increases, the rubber-like elastic body is cut inside. If it is not a rubber-like elastic material, or if it is cut at a part other than the semiconductive surface corona prevention layer, the cut surface is covered with an insulating film. Contact is impaired. However, according to the present invention, since the semiconductive rubber-like elastic body is exposed on the cut surface, due to thermal expansion,
Even if the contact position between the surface corona prevention layer 3 and the stator core 40 is relatively displaced, the electrical contact is maintained at the new contact position, so that the contact density is kept large regardless of the operation conditions. Can be.

FIGS. 1 to 5 and FIGS. 10 to 14 are partial sectional views showing a main part of a stator of a rotating electric machine, for example, a high-voltage rotating electric machine. In each of the drawings, the stator core 40 is represented by a rectangle having a slot in cross section, but this takes various shapes in accordance with the mode of the rotating electric machine. Known configurations can be used for other configurations such as the rotor of the rotating electric machine, the rotor bearings, and the casing.

In comparison with the harmonic voltage included in the inverter power supply, the surface corona prevention layer was burned by a surge voltage having a peak value of 1 kV in the comparative example.
Even when kV was applied, the surface corona prevention layer did not burn out.

[0034]

According to the present invention, it is possible to prevent burning of a high-voltage rotating electric machine.

Further, according to the present invention, a high-voltage rotating electric machine having a stator coil having a stable surface corona protection layer can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross-sectional structure of a slot coil according to an embodiment of the present invention.

FIG. 2 is a diagram showing a cross-sectional structure of a slot coil according to another embodiment of the present invention.

FIG. 3 is a diagram showing a cross-sectional structure of a slot coil according to another embodiment of the present invention.

FIG. 4 is a diagram showing a cross-sectional structure of a slot coil according to another embodiment of the present invention.

FIG. 5 is a diagram showing a cross-sectional structure of a slot coil according to another embodiment of the present invention.

FIG. 6 is a diagram showing a coil structure of a comparative example.

FIG. 7 is a diagram showing a model of a contact portion between a stator coil surface corona prevention layer and a stator core.

FIG. 8 is a diagram showing a potential of a stator coil surface corona prevention layer.

FIG. 9 is a diagram showing a potential of a stator coil surface corona prevention layer in the case where there is a contact portion adjacent thereto.

FIG. 10 is a diagram showing a cross-sectional structure of a slot coil according to another embodiment of the present invention.

FIG. 11 is a diagram showing a sectional structure of a slot coil according to another embodiment of the present invention.

FIG. 12 is a diagram showing a cross-sectional structure of a slot coil according to another embodiment of the present invention.

FIG. 13 is a diagram showing a cross-sectional structure of a slot coil according to another embodiment of the present invention.

FIG. 14 is a diagram showing a cross-sectional structure of a slot coil according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Coil conductor, 2 ... Coil insulating layer, 3 ... Surface corona prevention layer, 4 ... Semi-conductive laminate, 5 ... Semi-conductive resin, 6 ... Corrugated semi-conductive laminate, 7 ... Rubber-like semi-conductive Sex liner, 8 ...
A semi-conductive liner containing high dielectric particles, 9 a semi-conductive liner without surface protrusions, 10 a release semi-conductive liner, 11 an insulating laminate, 12 a semi-conductive resin coated semi-conductive laminate,
13: corrugated semiconductive laminate, 15: release resin, 20:
Coil, 22: liner, 40: stator core, 41: wedge, 50: end corona prevention layer, 60: contact part.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Mitsuhiro Nitobe 3-1-1 Sachimachi, Hitachi-City, Ibaraki Pref. Hitachi, Ltd. Hitachi Works (72) Inventor Akio Saito 3-Chome, Sachimachi, Hitachi-City, Ibaraki No. 1 Hitachi, Ltd., Hitachi Works (72) Inventor Keiji Suzuki 3-1-1, Sachimachi, Hitachi, Hitachi, Ibaraki Prefecture Inside Hitachi Works, Hitachi, Ltd. (72) Inventor Hiroyuki Suzuki, Hitachi, Sachi, Ibaraki 3-1-1, Machi-cho, Hitachi Works, Ltd. Hitachi Works (72) Inventor Yoshikiyo Kashiwa 3-1-1, Komachi, Hitachi, Ibaraki Prefecture F-term, Hitachi Works, Hitachi Works 5H604 AA01 BB01 BB03 BB09 BB14 CC01 CC05 CC13 CC16 DA19 PB03 PD02 PD06

Claims (14)

[Claims] The present invention is driven by a circuit using a semiconductor switching element, a corona prevention layer is provided on a surface of a coil, and a loss due to a charging current of a coil insulation layer in all contact portions between the surface corona prevention layer and an iron core is reduced. And a rotating electric machine having a width of 1 W or less per 1 mm of a peripheral length of a contact portion. 2. A circuit driven by a semiconductor switching element, having an insulating base mainly composed of mica on a coil conductor, a semiconductive tape on an outermost layer, and a thermosetting resin. A rotating electric machine having a coil and a configuration in which a semiconductive tape is adhered to an iron core. 3. A rotating electric machine driven by a circuit using a semiconductor switching element, wherein an insulating base mainly composed of mica is wound on a coil conductor a predetermined number of times, and a semiconductive tape is wound on an outermost layer. A rotating electric machine having a coil impregnated with a thermosetting resin and a semiconductive tape having rubber-like elasticity. 4. A rotating electric machine driven by a circuit using a semiconductor switching element, wherein an insulating base mainly composed of mica is wound on a coil conductor a predetermined number of times, and a semiconductive tape is wound on an outermost layer. A rotating electric machine having a coil impregnated with a thermosetting resin and having a semiconductive cured resin layer provided between a semiconductive tape and an iron core. 5. A rotating electric machine driven by a circuit using a semiconductor switching element, wherein an insulating base mainly composed of mica is wound on a coil conductor, a semiconductive tape is wound, and a gap between the coil conductor and the iron core is provided. A rotating electric machine having a structure in which a semiconductive liner is inserted into a coil and impregnated with a thermosetting resin, and the semiconductive liner is bonded to an iron core. 6. A rotating electric machine driven by a circuit using a semiconductor switching element, wherein an insulating base mainly composed of mica is wound on a coil conductor, a semiconductive tape is wound, and a thermosetting resin is applied. A rotating electric machine having an impregnated coil and a corrugated semiconductive laminated elastic plate arranged between the coil and the iron core. 7. In a coil of a rotating electric machine driven by a circuit using a semiconductor switching element, carbon particles are provided in at least one outermost layer of an insulating layer mainly composed of mica or at least one portion between the coil and an iron core. And a semiconductive layer containing particles of high dielectric constant such as silicon carbide, zinc oxide or titanium oxide. 8. A rotating electric machine driven by a circuit using a semiconductor switching element, wherein an insulating base mainly composed of mica is wound on a coil conductor, a semiconductive tape is wound, and a gap between the coil conductor and the iron core is provided. A rotating electric machine having a coil in which a semiconductive liner is inserted and a thermosetting resin is impregnated, and a film is included in at least a part of an insulating base material mainly composed of mica. 9. The rotating electric machine according to claim 8, wherein the semiconductive liner is made of a semiconductive material having no projection on its surface. 10. A rotating electric machine driven by a circuit using a semiconductor switching element, wherein an insulating base mainly composed of mica is wound on a coil conductor, a semi-conductive tape is wound, and a gap between the coil conductor and an iron core is provided. A rotating electric machine having a coil in which a semiconductive liner is inserted and impregnated with a thermosetting resin, and the semiconductive liner is made of a material having rubber-like elasticity. 11. A rotating electric machine driven by a circuit using a semiconductor switching element, wherein an insulating base mainly composed of mica is wound on a coil conductor, a semiconductive tape is wound, and a gap between the coil conductor and the iron core is provided. A rotating electric machine having a coil in which a semi-conductive liner is inserted and impregnated with a thermosetting resin, and the semi-conductive liner is made of a crepe-like material. 12. A rotating electric machine driven by a circuit using a semiconductor switching element, wherein an insulating base mainly composed of mica is wound on a coil conductor, a semiconductive tape is wound, and a gap between the coil conductor and the iron core is provided. In a coil impregnated with a thermosetting resin by inserting a semiconductive liner into the core, the semiconductive liner is filled with silicone resin or fluorocarbon resin filled with carbon particles on the coil side or core side surface of the core side. A rotating electric machine characterized by using a material coated with a conductive resin. 13. A rotating electric machine driven by a circuit using a semiconductor switching element. A semiconductive external corona is provided on a surface of a ground insulating layer of two upper and lower stator coils in slots formed in a stator core. With a prevention layer, the coil surface corona prevention layer is formed of a semiconductive tape in which a glass particle or a polyamide nonwoven fabric is coated with carbon particles or a mixture of carbon particles and carbon fiber, and one of the surface corona prevention layers is formed. The surface is brought into contact with the stator core slot wall via a semiconductive laminate, and the semiconductive laminate has a semiconductive resin on the coil side or the coil side and the stator core side, and has an opposite side. Inserts a corrugated semiconductive elastic laminate, places a semiconductive laminate between the bottom surface of the lower coil and the slot wall, and between the upper and lower coils, and connects the wedge with the upper coil. Rotary electric machine corrugated insulated elastic laminates from wedge, the wedge under insulation laminate disposed. 14. A rotating electric machine driven by a circuit using a semiconductor switching element, wherein a semi-conductive external corona is provided on a surface of a ground insulating layer of upper and lower two stator coils in slots formed in a stator core. It is formed of a semiconductive tape having a structure in which a carbon tape or a mixture of carbon particles and a carbon fiber is coated on a glass tape substrate having a coil surface corona prevention layer, which is provided with an anti-corona prevention layer. Face is in contact with the stator core slot wall, the other side inserts a corrugated semiconductive elastic laminate, and furthermore, a semiconductive laminate between the bottom surface of the lower coil and the slot wall and between the upper and lower coils. A rotating electric machine in which a wavy plate-like insulating elastic laminate and a wedge-lower insulating laminate are arranged between a wedge and an upper coil from the wedge side.